Design of bounded feedback controls for linear dynamical systems by using common Lyapunov functions

For a linear dynamical system,we address the problem of devising a bounded feedback control,which brings the system to the origin in finite time.The construction is based on the notion of a common Lyapunov function.It is shown that the constructed control remains effective in the presence of small perturbations.

Frequency compensation control method for opposedpiston two-stroke folded-cranktrain engine's common rail system by loop-shaping theory

A frequency compensation control method for the opposed-piston two-stroke folded-cranktrain（ OPFC） diesel engine＇s common rail system is presented as a result of the study of the loop-shaping theory. A common rail working process and the classical frequency control theory are combined to construct a frequency restriction of common rail pressure. A frequency compensator is utilized to improve the robustness of multiplicative perturbations and disturbance. The loop-shaping method has been applied to design the common rail pressure controller of the OPFC diesel engine. Simulation and bench test results show that in the condition of perturbation that comes from the effect of injection,multi-injection,fuel pumping of a pre-cylinder,and instantaneous pressure fluctuation,the controller indicates high precision. Compared with the original controller,this method improves the control precision by 67. 3%.

VB6中Common Dialog控件一次选择多个文件后的分离

本文介绍Common Dialog对话框选择多个文件,文件名的分离,Common Dialog新建,打开,保存文件的编程方法。

Control of switched systems with actuator saturation

This paper is concerned with controller synthesis for linear switched systems with actuator saturation. Based on common Lyapunov function technique and multiple-Lyapunov function technique, two methods for designing state feedback controller are proposed respectively in terms of linear matrix inequalities for the switched systems with saturation. An approach on enlarging the attractive domain is then investigated, The application of the presented approach is illustrated finally by a numerical example.

Effect of common salt on laboratory reared immature stages of Aedes aegypti(L)

Objective:To observe the effect of common salt(NaCl) on immature stages of laboratory reared Aedes aegypti(L).Methods:A laboratory colony of Aedes aegypti mosquitoes of Rajahmundry strain was established in the laboratory of National Institute for Communicable Disease(NICD), Rajahmundry unit at(26±2)℃with relative humidity of(70±10)%.1.00%,1.25%and 1.50% solutions of common salt(NaCl) were selected to observe the susceptibility status of immature stages of Aedes aegypti in laboratory.Results:Fifty percent larvae of Aedes aegypti died within 19,31 and 48 hours when exposed to 1.50%,1.25%and 1.00%common salt solution, respectively.Ninety percent of the larvae died within 29,57 and 108 hours when exposed to the same salt solutions,respectively.Very high pupal mortality was observed varying from 81.8% to 40.0%.Formation of pupae was found inversely proportional in the presence of concentration of common salt in breeding water.Conclusions:With easy availability,less toxicity and long lasting nature,common salt may be applied in unused containers,especially in junkyards where surveillance mechanism is poor along with other conventional vector control methods in order to control breeding of Aedes aegypti,the vector of dengue/ dengue hemorrhagic fever and chikungunya.

STRATEGY FOR DIESEL ROTARY ENGINE WITH COMMON RAIL INJECTION SYSTEM

A direct injection low compression ratios diesel rotary engine is designed and studied to find the appropriate application of the electronic controlled high pressure common rail injection system. Current development focuses on the applied fuel injection and ignition strategies, especially concerning the combustion configurations of injectors, ignition source, and combustion chamber. The prototype engine, equipped with Bosch common rail system and high performance electronic control unit （ECU）, is designed correspondingly. Studies show that the integration of a common rail injection system and the main and pilot duel injectors configurations, assisted with glow plug ignition device and flexible ECU, represents a promising approach to improve the potential of the low compression ratios diesel rotary engine. Currently the engine can run at 6 kr · min^-1 steadily and the power is about 68 kW/（4 kr ·min^- 1）.

Design and Comparison of Controller for the Reduction of Conducted Electromagnetic Interference in an Inverter

This paper presents the design of a controller for the measurement and reduction of conducted Electro Magnetic Interference (EMI) caused in the power electronic circuits. The conducted EMI is also separating the Common Mode (CM) and Differential Mode (DM) simultaneously using Line Impedance Stabilization Network (LISN). EMI is mitigated by the fuzzy controller. By comparing common mode voltage with the standard reference value, the generated error can be minimized by using fuzzy controller. Fuzzy controller is varying the PWM signal of the power electronic switching devices for reducing the electromagnetic interference. In this paper, comparison of PI and fuzzy controller of the open loop and closed loop models are implemented using MATLAB® SIMULINK for measurement and reduction of the EMI level;and also simulation results of the PI controller and fuzzy controller analysis are presented in this paper. The fuzzy controller is provided to achieve the EMI level of the inverter within the standard limit.

Adaptive fuzzy tracking control for a class of switched MIMO nonlinear systems

An adaptive fuzzy tracking control scheme is presented for a class of switched multi-input-multi-output (MIMO) nonlinear systems with disturbances under arbitrary switching. Adaptive fuzzy systems are employed to approximate the unknown functions on line,and a systematic framework for adaptive fuzzy tracking controller design is given,where the dynamic surface control (DSC) approach is used to solve the problem of "explosion of complexity"in the backstepping design procedure. According to the common Lyapunov function theory,it is proved that the proposed controller can guarantee the boundedness of all signals in the closed loop system. Finally,the simulation results demonstrate the validity of the control approach.

Model Reference Adaptive Control for Switched Systems with Closed-loop Reference Model Under Arbitrary Switching

This paper explores the model reference adaptive control problem for a class of switched linear systems under arbitrary switching with no need for the measurability of the system state.Based on the state of reference model and the measurable output error, adaptive laws and controllers are designed for switched systems.Each subsystem may have its individual reference model and controller, which increases the design flexibility.The introduction of the closed-loop reference model is to get a better transient performance of the whole switched systems.A numerical example is provided to verify the effectiveness of the main results.

A Double-Blind, Randomized, Placebo-Controlled Nutritional Study Using an Insoluble Yeast Beta-Glucan to Improve the Immune Defense System

Purpose: In a placebo-controlled, double-blind, randomized clinical trial, the effect of an insoluble yeast beta-glucan preparation on the incidences of common colds and its effect on common cold symptoms were compared to placebo. Methods: 100 healthy participants with recurring infections were randomly assigned to receive either placebo or yeast beta-glucan (Yestimun?;n = 50 each group) over a period of 26 weeks. The subjects had to document each common cold episode in a diary, and rate 6 predefined infections symptoms on a 3-point rating scale during an infection period, resulting in an infection score. The common cold episodes were confirmed by the investigators. Results: A total of 171 common cold episodes were documented. Of these, 76 were experienced by 38 subjects in the beta-glucan group and 96 were experienced by 48 subjects in the placebo group (p = 0.406). The beta-glucan group had significantly more subjects without incidences of common cold than the placebo group (15.6% vs 2.0%;p = 0.019). During the most intense infection season (first 13 weeks of the study), the beta-glucan group had significantly less infections compared to placebo (p = 0.02). Beta-glucan significantly reduced the typical cold symptoms (“sore throat and/or difficulty swallowing”, “hoarseness and/or cough” and “runny nose”) as opposed to placebo. Conclusion: The present study demonstrates a prophylactic effect of yeast beta-glucan on the occurrence of common colds as opposed to placebo. In addition, when these episodes occurred, they were from the beginning less pronounced and subsided faster.

H-infinity control for cascade minimum-phase switched nonlinear systems

This paper is concerned with the H-infinity control problem for a class of cascade switched nonlinear systems. Each switched system in this class is composed of a zero-mput asymptotically stable nonlinear part, which is also a switched system, and a linearizable part which is controllable. Conditions under which the H-infinity control problem is solvable under arbitrary switching law and under some designed switching law are derived respectively. The nonlinear state feedback and switching law are designed. We exploit the structural characteristics of the switched nonlinear systems to construct common Lyapunov functions for arbitrary switching and to find a single Lyapunov function for designed switching law. The proposed methods do not rely on the solutions of Hamilton-Jacobi inequalities.

Grid Interconnection of Wind Energy System at Distribu-tion Level Using Intelligence Controller

Wind generation is being increasingly connected at distribution level due to increasing load demand. Permanent magnet synchronous generator (PMSG) is connected to?the wind turbine directly. Through the full power control of AC-DC-AC converters, the electrical power is then connected to the power grid. The power conversion circuits are made up of generator-side three phase diode rectifiers, boost converter and the grid-side three bridges and four wire inverters. A boost converter is controlled through an intelligence controller to maintained DC power constant despite of Variable output of PMSG, the grid-connected operation is constructed using the hysteresis current control method. The inverter is controlled to perform following function 1) power converter to inject power generated from RES to the grid, and 2) shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current. The model is implemented in MATLAB/ Simulink using sim power system.

Preliminary Evaluation of Biocontrol Agents against Maize Pathogens <i>Exserohilum turcicum</i>and <i>Puccinia sorghi</i>in Field Assays

Exserohilum turcicum and Puccinia sorghi cause foliar fungal diseases that affect maize crop in Argentina. These diseases, northern leaf blight and common rust respectively, are presented each year with different levels of severity affecting significantly the yield in susceptible hybrids. Disease control usually consists in the use of resistant cultivars and chemical control. Biological control as a preventive method is a viable alternative to evaluate. The aims of this study were to evaluate the natural incidence of both foliar diseases in maize after application of two antagonists, to determine the survival of the antagonists in the maize phyllosphere and to evaluate the effect of inoculation on grain yield at harvest. Plants treated with both biological control agents showed significant reductions in the incidence of both foliar diseases. In northern leaf blight the reduction was higher than 50% during 40 days in plants treated with Bacillus spp. Moreover, grain yield was significantly higher as compared to control treatments.

Secure and Performant Handling CIM-Based Data Streams in Control Room Software Interaction for Multi Vendor Solutions

Due to the increasing share of renewable energy, new requirements are placed on control room software. Such software is often exclusive to the supplier, but other suppliers could offer new and better methods. For security reasons, external applications often have no direct data access to control room software. Such software can provide information about the power grid via a periodic file transfer in CIM (Common Information Model) format. These files are often very large, containing complete records, delivering information not always relevant to the external applications. Extracting the relevant information required by external applications can be time-consuming, thus presenting a problem for time-critical applications. This paper presents a method allowing different applications to efficiently access the relevant data from the massive data stream contained in the CIM files. This method has been tested with a distribution system operator and clearly increases performance, allowing different applications to access the relevant data.

Discussion on the Main Points of Construction Quality Control of Geological Hazard Management Engineering

In recent years, geological disasters have occurred frequently. This not only has a serious impact on urban construction, but also directly threatens the safety of life and property. In response to this situation, the control of the construction quality of the geological disaster management process must be strengthened to improve the construction quality of the treatment process. This paper mainly introduces the characteristics of geological hazard management engineering, common geological hazards and geological hazard treatment engineering, and expounds the key points and control measures of geological hazard management engineering quality control, so as to improve the construction quality of geological hazard management engineering.

新型混合式贯通牵引供电系统及其复合控制策略

电分相与负序等电能质量问题是制约电气化铁路向高速化、重载化发展的桎梏。贯通牵引供电系统为消弭上述问题提供了契机,但既有贯通方案依然存在所需器件数目多、改造成本高、可靠性差等弊端。为此,在充分利用既有牵引变压器基础上,该文设计一种新型混合式贯通牵引供电装置。该装置通过共直流侧与功率均分手段有效抵消输入侧纹波功率,降低有源/无源器件数目与电容容量。同时,针对直流侧二次纹波与负荷功率冲击,提出一种输入端口复合控制策略,有效解决纹波传递与冲击波动问题。最后通过仿真与实验验证所提装置及其控制策略的可行性与可靠性。

The Efficacy and Safety of a Patent Pending Combination of Ginger and Goldenrod Extracts on the Management of Cold Symptoms: A Randomized, Double-Blind Controlled Trial

Objective: In a randomized, double-blind, exploratory, active-controlled trial, the efficacy and safety of a patent-pending combination of Ginger and Goldenrod extracts (BDI-630) in alleviating cold symptoms in community-dwelling adults was compared to a combination of standardized amounts of Echinacea (EC) components. Methods: 44 healthy adults, experiencing new onset of cold symptoms were randomly assigned to receive either BDI-630 (900 mg) or EC (500 mg) twice daily for 10 days. The severity of cold symptoms and the quality of life was assessed by self-reporting of subjects using the Wisconsin Upper Respiratory Symptom Survey (WURSS-21? 2004). Results: The intent-to-treat population (ITT) consisted of 44 subjects (n = 22 for BDI-630;n = 22 for EC). The modified ITT (mITT) population consisted of 40 subjects, excluding four subjects with major protocol deviations related to inclusion/exclusion criteria and/or use of prohibited drugs from the efficacy analysis (n = 3 for BDI-630 and n = 1 for EC). Results indicated a sig-nificant difference between the two groups: the superiority of BDI-630 over EC was particularly noticeable between Day 1 and Day 7, as demonstrated by a 14-fold difference of the mean percentage of change of total score from baseline in the mITT population. Adverse events (AEs) following the intake of BDI-630 were mostly limited to mild gastrointestinal intolerance in less than 10% of the subjects. Conclusions: BDI-630 was shown to be more effective than EC in alleviating cold symptoms in the adult population, particularly during the first 7 days of treatment. BDI-630 was very well tolerated by all subjects.

控释尿素与普通尿素配施对橡胶树叶片和胶乳养分及产量的影响

为了明确控释尿素与普通尿素配施在橡胶树上的应用效果,通过2年田间试验,研究了减氮条件下控释尿素与普通尿素不同比例配施对橡胶树产量、叶片和胶乳矿质养分及土壤氮含量的影响,为橡胶树栽培管理中合理施氮提供技术支撑。结果表明:控释尿素与普通尿素配施可提高橡胶树干胶产量和叶片氮含量,与常规施肥相比,橡胶树干胶产量增幅为16.28%~39.13%(2021年)和7.94%~9.69%(2022年),叶片氮含量增幅为10.54%~19.17%(2021年)和10.24%~21.50%(2022年),控释尿素与普通尿素配施处理叶片氮含量均处于正常值以上。控释尿素与普通尿素配施还能够增加胶园肥穴土壤碱解氮含量,较常规施肥增加了11.27%~80.36%。控释尿素与普通尿素配施比例为50∶50时,橡胶树干胶产量(2022年)、叶片氮含量(2021—2022年)和土壤碱解氮含量(2021—2022年)均显著高于常规施肥。综上所述,在本试验条件下,控释尿素与普通尿素配施比例为50∶50能够获得较高的干胶产量,可改善叶片营养状况,维持土壤氮水平,有利于实现橡胶树施肥管理的绿色协同增效。

永磁同步电机模型预测转矩控制共模电压抑制研究

针对永磁同步电机模型预测转矩控制共模电压较大的问题,对比分析了磁链、转矩和共模电压共同控制、直接去除零电压矢量和虚拟零电压矢量三种抑制共模电压的方法。仿真结果表明,三种方法均可有效抑制共模电压。前两种方法均未采用零电压矢量,导致磁链脉动和转矩脉动增大;虚拟零电压矢量方法既保留了零电压矢量,又有效抑制了共模电压,但开关频率有所增大;动态虚拟零电压矢量选择开关次数最小的零电压矢量生成方式,可在控制性能基本相当的前提下,有效减小开关频率,综合性能最优。

基于自然容错开关表的五相永磁同步电机直接转矩控制

五相永磁同步电机(permanent-magnetsynchronous motor,PMSM)传统直接转矩控制(direct torque control,DTC)存在相电流畸变严重、共模电压(common-modevoltage,CMV)高、转矩和磁链脉动大等问题,且无法实现相开路故障情况下的无扰运行。为解决上述问题,提出一种基于自然容错开关表的DTC策略。该策略根据PMSM开路故障前后基电压矢量的特点以及三次平面合成电压矢量为零的原则,构建虚拟矢量(virtual vector,VV),设计故障前后同一套自然容错开关表,进而不但抑制了故障导致的转矩脉动,而且在故障前后均能降低三次谐波电流、减小转矩和磁链脉动、抑制CMV。实验结果验证所提策略的可行性。