Non-Fragile Controller Design for 2-D Discrete Uncertain Systems Described by the Roesser Model

This paper is concerned with the design problem of non-fragile controller for a class of two-dimensional (2-D) discrete uncertain systems described by the Roesser model. The parametric uncertainties are assumed to be norm-bounded. The aim of this paper is to design a memoryless non-fragile state feedback control law such that the closed-loop system is asymptotically stable for all admissible parameter uncertainties and controller gain variations. A new linear matrix inequality (LMI) based sufficient condition for the existence of such controllers is established. Finally, a numerical example is provided to illustrate the applicability of the proposed method.

Robust Suboptimal Guaranteed Cost Control for 2-D Discrete Systems Described by Fornasini-Marchesini First Model

This paper considers the guaranteed cost control problem for a class of two-dimensional (2-D) uncertain discrete systems described by the Fornasini-Marchesini (FM) first model with norm-bounded uncertainties. New linear matrix inequality (LMI) based characterizations are presented for the existence of static-state feedback guaranteed cost controller which guarantees not only the asymptotic stability of closed loop systems, but also an adequate performance bound over all the admissible parameter uncertainties. Moreover, a convex optimization problem is formulated to select the suboptimal guaranteed cost controller which minimizes the upper bound of the closed-loop cost function.

Robust Non-Fragile Control of 2-D Discrete Uncertain Systems: An LMI Approach

This paper considers the problem of robust non-fragile control for a class of two-dimensional (2-D) discrete uncertain systems described by the Fornasini-Marchesini second local state-space (FMSLSS) model under controller gain variations. The parameter uncertainty is assumed to be norm-bounded. The problem to be addressed is the design of non-fragile robust controllers via state feedback such that the resulting closed-loop system is asymptotically stable for all admissible parameter uncertainties and controller gain variations. A sufficient condition for the existence of such controllers is derived based on the linear matrix inequality (LMI) approach combined with the Lyapunov method. Finally, a numerical example is illustrated to show the contribution of the main result.

Delay-Dependent Robust H∞ Control for Uncertain 2-D Discrete State Delay Systems Described by the General Model

This paper considers the problem of delay-dependent robust optimal H∞ control for a class of uncertain two-dimensional (2-D) discrete state delay systems described by the general model (GM). The parameter uncertainties are assumed to be norm-bounded. A linear matrix inequality (LMI)-based sufficient condition for the existence of delay-dependent g-suboptimal state feedback robust H∞ controllers which guarantees not only the asymptotic stability of the closed-loop system, but also the H∞ noise attenuation g over all admissible parameter uncertainties is established. Furthermore, a convex optimization problem is formulated to design a delay-dependent state feedback robust optimal H∞ controller which minimizes the H∞ noise attenuation g of the closed-loop system. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed method.

Robust Optimal H∞ Control for Uncertain 2-D Discrete State-Delayed Systems Described by the General Model

This paper investigates the problem of robust optimal H∞ control for uncertain two-dimensional (2-D) discrete state-delayed systems described by the general model (GM) with norm-bounded uncertainties. A sufficient condition for the existence of g-suboptimal robust H∞ state feedback controllers is established, based on linear matrix inequality (LMI) approach. Moreover, a convex optimization problem is developed to design a robust optimal state feedback controller which minimizes the H∞ noise attenuation level of the resulting closed-loop system. Finally, two illustrative examples are given to demonstrate the effectiveness of the proposed method.

2-D algebraic test for robust stability of time-delay systems with interval parameters

The robust stability test of time-delay systems with interval parameters can be concluded into the robust stability of the interval quasipolynomials. It has been revealed that the robust stability of the quasipolynomials depends on that of their edge polynomials. This paper transforms the interval quasipolynomials into two-dimensional （2-D） interval polynomials （2-D s-z hybrid polynomials）, proves that the robust stability of interval 2-D polynomials are sufficient for the stability of given quasipolynomials. Thus, the stability test of interval quasipolynomials can be completed in 2-D s-z domain instead of classical 1-D s domain. The 2-D s-z hybrid polynomials should have different forms under the time delay properties of given quasipolynomials. The stability test proposed by the paper constructs an edge test set from Kharitonov vertex polynomials to reduce the number of testing edge polynomials. The 2-D algebraic tests are provided for the stability test of vertex 2-D polynomials and edge 2-D polynomials family. To verify the results of the paper to be correct and valid, the simulations based on proposed results and comparison with other presented results are given.

Event-triggered robust guaranteed cost control for two-dimensional nonlinear discrete-time systems

An event-triggered scheme is proposed to solve the problems of robust guaranteed cost control for a class of two-dimensional(2-D)discrete-time systems.Firstly,an eventtriggered scheme is proposed for 2-D discrete-time systems with parameter uncertainties and sector nonlinearities.Then,according to the Lyapunov functional method,the sufficient conditions for the existence of event-triggered robust guaranteed cost controller for 2-D discrete-time systems with parameter uncertainties and sector nonlinearities are given.Furthermore,based on the sufficient conditions and the linear matrix inequality(LMI)technique,the problem of designing event-triggered robust guaranteed cost controller is transformed into a feasible solution problem of LMI.Finally,a numerical example is given to demonstrate that,under the proposed event-triggered robust guaranteed cost control,the closed-loop system is asymptotically stable and fewer communication resources are occupied.

Duality of 2-D singular systems of Roesser models

In this paper, the properties and concepts of dual systems of the two-dimensional singular Roesser models （2-D SRM） are studied. Two different concepts of the dual systems are proposed for the 2-D SRM. One is derived from the duality defined for two-dimensional singular general models （2-D SGM）-called the S-dual systems; the other one is defined based on 2-D SRM in a traditional sense-called the T-dual systems. It is shown that if a 2-D SRM is jump-mode free or jump-mode reachable, then it can be equivalently transformed into a canonical form of a 2-D SRM, for which the T-duality and the S-duality are equivalent. This will be of some perspective applications in the robust control of 2-D SRM.

Output Feedback Robust H_(∞) Control for Discrete 2D Switched Systems

The two-dimensional(2-D)system has a wide range of applications in different fields,including satellite meteorological maps,process control,and digital filtering.Therefore,the research on the stability of 2-D systems is of great significance.Considering that multiple systems exist in switching and alternating work in the actual production process,but the system itself often has external perturbation and interference.To solve the above problems,this paper investigates the output feedback robust H_(∞)stabilization for a class of discrete-time 2-D switched systems,which the Roesser model with uncertainties represents.First,sufficient conditions for exponential stability are derived via the average dwell time method,when the system’s interference and external input are zero.Furthermore,in the case of introducing the external interference,the weighted robust H_(∞)disturbance attenuation performance of the underlying system is further analyzed.An output feedback controller is then proposed to guarantee that the resulting closed-loop system is exponentially stable and has a prescribed disturbance attenuation levelγ.All theorems mentioned in the article will also be given in the form of linear matrix inequalities(LMI).Finally,a numerical example is given,which takes two uncertain values respectively and solves the output feedback controller’s parameters by the theorem proposed in the paper.According to the required controller parameter values,the validity of the theorem proposed in the article is compared and verified by simulation.

Efficacy of Selected Herbicide Programs in 2,4-D Tolerant Cotton (<i>Gossypium hirsutum</i>L.)

The use of transgenic crops has grown significantly over the past couple of decades. Many agronomic crops produced today are tolerant to glyphosate. Glyphosate-tolerant crops were commercially introduced in 1996, and, about nine years later, glyphosate-resistant Palmer amaranth was confirmed in Georgia. Glyphosate-resistant weeds arose from reliance on postemergence only glyphosate programs to control weeds in crops. New transgenic traits for glufosinate and 2,4-D choline have been developed, and evaluations of stacked traits and concurrent use of multiple herbicides have provided additional tools in the management of glyphosate-resistant weeds. Field experiments were conducted in 2012 and 2013 at the Edisto Research and Education Center near Blackville, SC, USA to determine the efficacy of 2,4-D-based herbicide programs in transgenic cotton tolerant to 2,4-D choline, glyphosate, and glufosinate. The treatments provided good to excellent Palmer amaranth and pitted morningglory control in 2012 and 2013. Seed cotton yields across treatments ranged from 0 to 2057 kg ha-1. This new trait technology package in cotton permits in-season postemergence use of 2,4-D choline, a herbicide mode of action not previously used postemergence in cotton, which can control resistant weeds, including Palmer amaranth if applied at the proper growth stage.

Reaching law based sliding mode control for a frame structure under seismic load

Implementation of efficient vibration control schemes for seismically excited structures is becoming more and more important in recent years.In this study,the influence of different control schemes on the dynamic performance of a frame structure excited by El Centro wave,with an emphasis on reaching law based control strategies,is examined.Reaching law refers to the reachable problem and criteria for the sliding state of a control system.Three reaching laws are designed to present different sliding mode control strategies by incorporating a state space model that describes structural dynamic characteristics of a frame structure.Both intact and damaged structures are studied by using the aforementioned control strategies.The influence of different structural damage extents,control locations and reaching law based control methods are further investigated.The results show that the structure can be well controlled using the sliding mode strategy when the induced structural damage extent does not exceed the standard percentage for considering the structure was damaged,which is 20%reduction in structure stiffness,as reported in the literature.The control effectiveness is more satisfactory if the control location is the same as the direction of external excitation.Furthermore,to study the chattering phenomenon of the sliding mode control method,approximation and detail components extracted from the phase plots of the sliding mode control system are compared via wavelet transform at different scales.The results show that for the same type of control law,the system behaves with similar chattering phenomenon.

模糊控制系统的计算机设计与仿真的研究

该文提出了模糊控制系统的计算机设计和仿真方法 ,具体叙述了火电厂锅炉水位的模糊控制器设计 ,2 -D控制表的建立 ,以及模糊控制系统的计算机设计和仿真的实现 ,并得到了实际应用。该方法使模糊控制系统设计和仿真变得容易、直观且迅速。

调整系统控制量的模糊PID控制器的计算机设计与仿真

该文提出调整系统控制量的模糊PID控制器的计算机设计与仿真。以碱回收炉的水位控制为例具体论述调整系统控制量的模糊PID控制器的设计、2-D控制表的建立、以及控制器计算机设计与仿真的实现。借助MATLAB模糊控制工具箱和SIMULINK仿真工具进行的仿真实验表明,该控制器既吸收了模糊控制器良好的动态性能,又克服了模糊控制器静态性能较差的缺点。并且为碱回收炉上汽包水位控制提出了一种新的尝试。该控制器结构简单、参数调整方便、快捷。

The establishment of crystal position look-up table for positron emission tomography with block detectors

A method has been developed to establish the crystal position look-up table for positron emission tomography with block detectors. It is based on the principle that the counts in crystal position histogram obey the Gaussian mixture model (GMM). This method has taken full consideration of the characteristics of the GMM and the detector itself. The experimental results have proved that it is simple, reliable, and universal.

Active control of supersonic/hypersonic aeroelastic flutter for a two-dimensional airfoil with flap

The flutter, post-flutter and active control of a two-dimensional airfoil with control surface operating in supersonic/hypersonic flight speed regions are investigated in this paper. A three-degree-of-freedom dynamic model is established, in which both the cubic nonlinear structural stiffness and the nonlinear aerodynamic load are accounted for. The third order Piston Theory is employed to derive the aerodynamic loads in the supersonic/hypersonic airflow. Nonlinear flutter happens with a phenomenon of limit cycle oscillations (LCOs) when the flight speed is less than or greater than linear critical speed. The LQR approach is employed to design a control law to increase both the linear and nonlinear critical speeds of aerodynamic flutter, and then a combined control law is proposed in order to reduce the amplitude of LCOs by adding a cubic nonlinear feedback control. The dynamic responses of the controlled system are given and used to compare with those of the uncontrolled system. Results of simulation show that the active flutter control method proposed here is effective.

FPGA内嵌ROM表对DRAM控制的实现

指挥控制系统是现代军舰的灵魂,而肩负专用功能的电子模块组成了指挥控制系统的"躯体"。各种存储器件是存储数据的载体,对存储器件的控制和操作成为专用电子模块设计的重要组成部分。动态存储器(DRAM)是重要的存储器件,现场可编程门阵列(FPGA)在计算机硬件设计领域的应用也十分广泛。重点阐述了应用FPGA实现对DRAM的复杂控制,并由此提出了一种运用ROM表的简便方法,工程实践证明该方法具有广泛的通用性和较强的实用性。

Robust state feedback for uncertain 2-D discrete switched systems in the Roesser model

The design of robust H_(∞)controllers is considered here for a class of two-dimensional(2-D)discrete switched systems described by the Roesser model with polytopic uncertainties.Attention focuses on the design of a switched state feedback controller,which guarantees the robust asymptotic stability and a prescribedH_(∞)performance for the closed-loop system.By using multiple parameter-dependent Lyapunov functionals,and introducing some switched free-weighting matrices,a new sufficient condition for the robust H_(∞)performance analysis of uncertain 2-D discrete switched systems is developed.Furthermore,the design of switched state feedback controller is proposed in terms of linear matrix inequalities(LMIs).Illustrative examples are given to illustrate the effectiveness of the developed theoretical results.

因果图测试法在地铁网络应用软件合格性测试中的应用

结合长沙地铁2号线列车控制与诊断系统(长沙地铁2号线TCMS)网络应用软件合格性测试过程中的应用实例,对如何运用因果图测试法生成测试用例进行了详细的阐述与分析,可供其他类似软件的测试应用参考。

优秀男子自行车运动员强度训练的心率指标的量化控制

以6名河北优秀男子自行车运动员作为研究对象,应用polar表和protrainer5软件以及Team2团队心率系统对强度训练课进行监控与分析。本文主要针对场地自行车项目中的次最大强度和最大强度训练,通过心率指标的量化控制,更有效实现教练员的训练要求,快速提高运动员的专项能力。

双歧杆菌四联活菌片对血糖控制欠理想2型糖尿病患者肠道菌群及胰岛β细胞功能的影响

目的探讨双歧杆菌四联活菌片对血糖控制欠理想2型糖尿病(T2DM)患者肠道菌群及胰岛β细胞功能的影响。方法选取2016年3月至2017年3月在我院内科门诊治疗的血糖控制欠理想T2DM患者94例,随机分为观察组和对照组,各47例。两组患者均予以调整饮食、适量运动及控制血糖等治疗。观察组患者加用双歧杆菌四联活菌片1.5g/次,3次/d,温水送服,连用10周。观察并记录两组患者治疗前与治疗10周后血糖控制情况、肠道菌群和β细胞功能的变化。结果治疗10周后,两组患者FBG、2hPG和HbA1C均有不同程度下降(P<0.05或P<0.01),且观察组患者变化幅度更大(P<0.05);同时两组患者肠道乳杆菌和双歧杆菌数量增加,大肠埃希菌数量减少(P<0.05和P<0.01),且观察组变化幅度更大(P<0.05);两组患者HOMA-β水平均有不同程度上升,且观察组变化幅度亦大于对照组(P<0.05)。结论血糖控制欠理想T2DM患者予以双歧杆菌四联活菌片治疗不仅可促进胰岛β细胞功能的恢复,而且能纠正肠道菌群失调,恢复肠道微生态平衡,改善糖代谢功能,有利于血糖及糖化血红蛋白的控制。