Fractional Order Modeling of Human Operator Behavior with Second Order Controlled Plant and Experiment Research

Modeling human operator's dynamics plays a very important role in the manual closed-loop control system, and it is an active research area for several decades. Based on the characteristics of human brain and behavior, a new kind of fractional order mathematical model for human operator in single-input single-output (SISO) systems is proposed. Compared with the traditional models based on the commonly used quasilinear transfer function method or the optimal control theory method, the proposed fractional order model has simpler structure with only few parameters, and each parameter has explicit physical meanings. The actual data and experiment results with the second-order controlled plant illustrate the effectiveness of the proposed method. © 2014 Chinese Association of Automation.

A parameter optimization approach to robust PI-controller design for systems with interval plants

The purpose of this paper is to develop an analytic way for designing optimal PI-controllers for the interval plant family. Optimality means that the coefficient intervals of the plant stabilized by a PI-controller is maximized. It will be shown that the optimization problem can be formulated in terms of an eigenvalue minimization problem of matrix pairs of the form （H（h0, g0）, H（δ1,k, δ2,k））, where k= 1, 2, 3, 4 and both H（h0, g0） and H（δ1,k,δ2,k） are frequency independent Hurwitz-like matrices. A numerical example is provided to illustrate that optimal controller parameters can be successfully obtained by a two-dimensional search.

Advanced Coordinating Control System for Power Plant

The coordinating control system is popular used in power plant.This paper describes the advanced coordinating control by control methods and optimal operation,introduces their principals and features by using the examples of power plant op- eration.It is wealthy for automation application in optimal power plant operation.

The Development and Research on the Coordinate Control Strategy Between Turbine and Boiler in Fossil Power Plant

Based on the research on domestic and international automatic technical development in fossil power plant,the paper analyses the recent situation of the coordinate control system between turbine and boiler of domestic fossil Power Plant,provides the development thought of coordinate control system between turbine and boiler,and describes the application prospect in control system of fossil power plant combining with the application experience.

Effect of Antagonists and Plant Extracts in the Control of Protea Wilt (<i>F. oxysporum</i>)

In laboratory experiments were evaluated TRICHOD&reg, FOLIGUARD&reg, Trichoderma sp, and watery extracts of pine, marigold and eucalyptus, respectively, against F. oxysporum. There were no significant differences between TRICHOD&reg and FOLIGUARD&reg. The extract of marigold of 120 g/L was the best result in reducing the area of the colony of F. oxysporum. In field pots experiment were evaluated the extract of marigold (120 g/L), potassium phosphite (400 g/L), TRICHOD and benomyl (1.5 g/L) to control F. oxysporum. Treatments were applied to the soil, 15 days after inoculation with F. oxysporum. The best obtained heights were of 32 cm with extract of marigold 120 g/L, followed by potassium phosphite with 31 cm, and the control reached 26 cm of height. The treatment with an extract of marigold 120 g/L, obtained the best dry weight average of 6.5 g, statistically different from the control. The extract of marigold presented the best efficiency against the disease, because it reduced the length of the vascular symptom in 88.5%;followed by TRICHOD&reg, benomyl and potassium phosphite that showed reductions of 86, 85 and 84 percent, respectively.

Optimal Tuning of Plant-Friendly PID Controllers

A plant-friendly proportional-integral-derivative （PID） controller optimization framework is proposed to make tradeoffs among set-point response,controller output variations and robustness.The objective function is chosen as the weighted sum of the integral of squared time-weighted error and the integral of squared timeweighted derivative of the control variable with respect to set-point response,while the robustness of the system is guaranteed by constraints on gain and phase margins.Due to the complex structure of the constraints,the problem is solved by genetic algorithms.Simulation analysis show the proposed method could efficiently reduce the controller output variations while maintaining a short settling time.Based on the simulation results,iterative tuning rules for the weighting factor in the objective function are obtained,which allows efficient simple proportional-integral（PI） tuning formulae to be derived.

Distributed Model Predictive Control for Networked Plant-wide Systems With Neighborhood Cooperation

For large-scale networked plant-wide systems composed by physically(or geographically) divided subsystems, only limited information is available for local controllers on account of region and communication restrictions. Concerning the optimal control problem of such subsystems, a neighbor-based distributed model predictive control(NDMPC) strategy is presented to improve the global system performance. In this scheme, the performance index of local subsystems and that of its neighbors are minimized together in the determination of the optimal control input, which makes the local control decision also beneficial to its neighboring subsystems and further contributes to improving the convergence and control performance of overall system.The stability of the closed-loop system is proved. Moreover, the parameter designing method for distributed synthesis is provided.Finally, the simulation results illustrate the main characteristics and effectiveness of the proposed control scheme.

A review of selected parasitic plants in Nigeria:converting harms to benefits

Parasitic plants are challenging to agricultural crops and forestry development,which are sources of major revenues in several countries,including Nigeria.Nevertheless,parasitic plants are important to human society as they have an abundance of bioactive compounds with pharmacological relevance.Thus,it becomes expedient to know the benefits of these plants and potential means of management.This review discusses four selected parasitic plants in Nigeria,namely Viscum album,Striga hermonthica,Tapinanthus bangwensis and Cuscuta campestris.Relevant information about their pharmacological relevance and biocontrol was obtained from credible databases,including the National Library of Medicine,SCOPUS,and Google Scholar.The review showed that all four plants have been extensively studied for their antioxidant and antitumor properties.Also,antimicrobial and anti-inflammatory activities are common pharmacological values among parasitic plants.These are largely due to the presence of abundant beneficial classes of phytocompounds.Furthermore,there is an increasing number of biocontrol studies on the use of microorganisms,such as Phaeobotryosphaeria visci,Sphaeropsis visci,Pandoraea pulminicol,Colletotrichum gloeosporioides,and Fusarium oxysporum in controlling and managing these seemingly disastrous plants.It is hoped that this review will spur further studies into the conservation and proper management of parasitic plants using strategically developed biocontrol.

Effects of Plant Growth Promoting Rhizobacteria (PGPR) on In Vitro Bread Wheat (Triticum aestivum L.) Growth Parameters and Biological Control Mechanisms

Three endemic plants rhizosphere (Astragalus gombo Coss. & Dur., Daucus sahariensis Murb., Ononis angustissima Lam.), were used for actinomycetes isolation. Ninety-three (93) isolates have been screened to evaluate their antagonistic properties against phytopathogenic microorganisms and to determine their biocontrol properties against Fusarium culmorum, especially responsible for several cereal diseases like font’s seedlings, rust, and burn of ears. Four (04) isolates (D2, D5, D8, and AST1) have been in vitro tested to determine PGPR effect and biocontrol characters of bread wheat (Triticum aestivum L.), Hidhab (HD) variety cultivated in the Murashigue and Skoog (MS) culture medium. The aim of this study is the evaluation of antagonistic isolates of pathogenic fungi F. culmorum, without and within commercial fungicide (Tebuconazole, 60 g/l) solution. Our results showed clearly that these isolates have a significant effect on seed germination and seedling growth. However, results argue that these actinomycetes isolates show a very interesting activity compared to the commercial fungicide. As a result, these bacteria isolates can be used as biocontrol agents against Fusarium wilt disease of wheat, which have a beneficial effect on growth parameters.

A Novel Computerized Water Level Control System of PWR Steam Generator of Nuclear Power Plant

This paper presents a novel method to solve old problem of water level control system of pressurized water reactor (PWR) steam generator (SG) of nuclear power plant (NPP) .The level control system of SG plays an important role which effects the reliablity,safty,cost of SG and its mathematical models have been solved.A model of the conventional controller is presented and the existing problems are discussed. A novel rule based realtime control technique is designed with a computerized water level control (CWLC) system for SG of PWR NPP.The performance of this is evaluated for full power reactor operating conditions by applying different transient conditions of SG′s data of Qinshan Nuclear Power Plant (QNPP).

Self-Tuning Control Techniques for Wind Turbine and Hydroelectric Plant Systems

The interest on the use of renewable energy resources is increasing, especially towards wind and hydro powers, which should be efficiently converted into electric energy via suitable technology tools. To this aim, self-tuning control techniques represent viable strategies that can be employed for this purpose, due to the features of these nonlinear dynamic processes working over a wide range of operating conditions, driven by stochastic inputs, excitations and disturbances. Some of the considered methods were already verified on wind turbine systems, and important advantages may thus derive from the appropriate implementation of the same control schemes for hydroelectric plants. This represents the key point of the work, which provides some guidelines on the design and the application of these control strategies to these energy conversion systems. In fact, it seems that investigations related with both wind and hydraulic energies present a reduced number of common aspects, thus leading to little exchange and share of possible common points. This consideration is particularly valid with reference to the more established wind area when compared to hydroelectric systems. In this way, this work recalls the models of wind turbine and hydroelectric system, and investigates the application of different control solutions. Another important point of this investigation regards the analysis of the exploited benchmark models, their control objectives, and the development of the control solutions. The working conditions of these energy conversion systems will also be taken into account in order to highlight the reliability and robustness characteristics of the developed control strategies, especially interesting for remote and relatively inaccessible location of many installations.

Load Frequency Control of Small Hydropower Plants Using One-Input Fuzzy PI Controller with Linear and Non-Linear Plant Model

This study presents an intelligent approach for load frequency control (LFC) of small hydropower plants (SHPs). The approach which is based on fuzzy logic (FL), takes into account the non-linearity of SHPs—something which is not possible using traditional controllers. Most intelligent methods use two- input fuzzy controllers, but because such controllers are expensive, there is economic interest in the relatively cheaper single-input controllers. A non- linear control model based on one-input fuzzy logic PI (FLPI) controller was developed and applied to control the non-linear SHP. Using MATLAB/Si- mulink SimScape, the SHP was simulated with linear and non-linear plant models. The performance of the FLPI controller was investigated and compared with that of the conventional PI/PID controller. Results show that the settling time for the FLPI controller is about 8 times shorter;while the overshoot is about 15 times smaller compared to the conventional PI/PID controller. Therefore, the FLPI controller performs better than the conventional PI/PID controller not only in meeting the LFC control objective but also in ensuring increased dynamic stability of SHPs.

Stability of singular networked control systems with control constraint

Based on bounded network-induced time-delay, the networked control system is modeled as a linear time-variant singular system. Using the Lyapunov theory and the linear matrix inequality approach, the criteria for delay-independent stability and delay-dependent stability of singular networked control systems are derived and transformed to a feasibility problem of linear matrix inequality formulation, which can be solved by the Matlab LMI toolbox, and the feasible solutions provide the maximum allowable delay bound that makes the system stable. A numerical example is provided, which shows that the analysis method is valid and the stability criteria are feasible.

Control Effects of Bacillus subtilis DJ-6 and Pyraclostrobin Alone and in Combination Against Fusarium oxysporum

[Objective] This study was conducted to screen a synergistic biological fungicide complex to control Fusarium wilt, reducing the use of chemical pesticides. [Method] The inhibitory effects of Bacil us subtilis DJ-6 and pyraclostrobin alone or in combination at five ratios against Fusarium oxysporum were detected by mea-suring mycelium growth rate in laboratory tests. The growth promotion and disease control effect of combined or single use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000, 1∶2 000 and 1∶3 000 dilutions were detected in field trials. [Result] The EC50 values of combined use of B. subtilis DJ-6 and pyra-clostrobin at ratios of 1∶1, 1∶2, 1∶3, 1∶4 and 1∶5 against F. oxysporum were 5.311 5, 4.008 6, 3.570 6, 3.350 9 and 3.218 9 μg/ml, with the synergistic ratios （SR） of 2.28, 1.77, 1.53, 1.64, 1.11, among which the synergetic effect at 1∶1 was the best. The fungicidal activity of pyraclostrobin was greater than that of B. subtilis DJ-6 in laboratory tests. Field trials revealed that al the 1∶1 000, 1∶2 000 and 1∶3 000 dilu-tions of 20% pyraclostrobin·2×1011 cfu/g B. subtilis DJ-6 WP in combination, 1∶1 000 dilution of 1 ×1012 cfu/g B. subtilis DJ-6 WP and 1∶2 000 dilution of 250 g/L pyra-clostrobin EC promoted the growth of strawberry by increasing plant height, leaf petiole, leaf blade area and stem diameter. Among them, the treatments with 1∶1 000 and 1∶2 000 of 20% pyraclostrobin · 2×1011 cfu/g B. subtilis DJ-6 WP in combina-tion had better effects than other treatments. The control effects of al the treat-ments were measured 30 and 80 d after fungicide application. The control effects of 1∶1 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combina-tion were up to 100% and 93.11%, which were higher than those in al other treat-ments. The second highest control effects were found in the treatment with 1∶ 2 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination, they were 92.49% and 86.49%, higher than those in other treatments except the 1∶1 000 dilution of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 in combination. The control effects of 1∶3 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination were 82.61% and 72.42%, higher than those in treatment with 1∶1 000 dilution of 1×1012 cfu/g B. subtilis DJ-6 WP, but lower than those in treat-ment with 1∶2 000 dilution of 25% pyraclostrobin EC. [Conclusion] Al the results re-vealed that the combination use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000 to 1∶2 000 dilution had better control effect against strawberry Fusarium wilt.

Overview of Southern Blight in Chinese Medicinal Plants

The pathogen of southern blight, distribution and host species, damage symptoms and infection cycle, and the pathogenic mechanisms are introduced. Based on the introduction, the major factors affected the incidence of medicinal plants such as climatic conditions, soil conditions and cultivation conditions, etc. are further summarized, and the studies on the control of southern blight in Chinese medicinal plants are summarized from the aspects of agricultural control, biological control and chemical control, etc.

基于大数据技术的大蒜品质智能化调控研究

以进一步提升大蒜种植的智能性、品质性为目标,选取大数据处理及应用技术,针对大蒜种植过程的调控系统展开设计。考虑大蒜种芽、种植土壤条件等基础特点,结合不同种植调控下的大蒜培育状况,基于大数据架构平台组成,搭建用于智能化品质大蒜调控的数据处理模型。设计布局大数据应用的软件控制模块,配置相应的系统硬件结构,重点针对种芽朝向进行调控。展开品质化作业试验,结果表明:基于大数据技术的大蒜品质智能化调控系统设计,能够很好地运用数据计算与处理算法对大蒜种植运动过程各数据进行准确监测,通过及时的调控措施满足种芽朝向调整正确率要求,单粒合格率可达到95.40%,蒜芽漏充率可降低至3.15%,种植效率相对提升了6.37%,具有很好的推广价值。

基于数据挖掘模型的智能插秧机作业实践探究

以进一步优化插秧机的整机作业效率为研究目标,选取插秧机智能控制系统为研究对象,基于数据挖掘模型及算法理念展开实践应用探究。结合插秧机的作业特征及网控系统结构原理,从降低网络信号传输延迟及提升抗干扰能力角度搭建数据挖掘算法优化模型,并进行实际的插秧状态算法路径设计及控制指令下发,确保各个环节衔接准确。插秧作业结果表明:基于数据挖掘模型的插秧机智能化作业水平得到显著提升,挖掘算法精度与系统控制准确率分别可相对提升7.90%和5.75%,整机插植均匀度可达90.72%,对于插秧机的智能化开发与优化具有促进作用。

Effects of the Residues of Cuscuta campestris and Mikania micrantha on Subsequent Plant Germination and Early Growth

Cuscuta campestris, a dodder, can parasitize and suppress a scrambling herbaceous to semi-woody perennial vine, Mikania micrantha, one of the most destructive weeds in the world. To assess the effects of the mixed residue of C. campestris and M. micrantha on the subsequent plant community, we conducted a one-year experiment on the germination and seedling growth of subsequent plant community after the application of C. campestris. Seven treatments of varying proportions of C. campestris and M. mierantha residue on 21 subject trees and shrubs, which were commonly found in South China, resulted in a germination rate of 35.3% for all 8 715 seeds from 18 species, ranging from 5.7 to 81.9%; the remaining 3 species failed to germinate. ANOVA analysis showed that the residue did not affect the germination, growth, or mortality of the trees and shrubs. The germinated C. campestris seeds from the residue coiled the seedlings of most of the species, but less than 4% host death caused by C. campestris. In addition, the residue did not affect the germination of the herbaceous seedlings originating from the loam, and the similarity coefficients of the germinated seedlings between the treatments were very high. These results suggested that the residue had no negative impact on the germination and early seedling stages of the tree, shrub and grass species of the subsequent plant community. The use of C. campestris residue had a positive effect on the growth of M. micrantha, but it did not change the trend of M. micrantha being suppressed because re-parasitization occurred soon after the growth restarted. No negative effect was detected on the other species as a result of the parasitization of C. campestris or by the use of the mixed residue. This suggests that C. campestris is likely to be an effective and promising ecologically safe native herbaceous agent for controlling M. micrantha.

Mercury Emission From Coal-fired Power Plants in China

燃煤是最大的人为汞排放源之一，燃煤电厂的汞排放控制问题也越来越为人们所关注。该文将目前公布的中国电厂的汞排放数据进行筛选汇总，得到18个电厂的汞排放数据，通过对比和分析，总结出了符合我国燃煤电厂特点的一般性汞排放规律。结果表明：与美国煤种相比，我国的燃煤具有低氯、高灰的特性，这不利于汞的排放控制；循环流化床燃烧可能会因燃尽率的不同而较煤粉炉燃烧易获得较高的Hgp；空气污染控制设备的使用能够有效地减少汞排放，选择性催化还原＋静电除尘器／布袋除尘器＋石灰石-石膏湿法脱硫（SCR＋ESP／FF＋WFGD）组合的平均脱汞率可达71．48％；SCR的大规模应用可能会将汞大量转移到飞灰和脱硫石膏中，带来二次污染的问题。

PLANTSCAPE集散系统的可靠性技术

在引入一项新型集散控制系统用于工业生产过程时,研究它的可靠性是很有必要的,才能体现出该系统的应用价值。针对PLANTSCAPE集散系统应用中出现的问题,提出了具体的解决办法,从而提高发电机组的安全性和经济性。