Adaptive Robust Control for a Class of Uncertain MIMO Non-affine Nonlinear Systems

In this paper, the adaptive robust tracking control scheme is proposed for a class of multi-input and multioutput(MIMO) non-affine systems with uncertain structure and parameters, unknown control direction and unknown external disturbance based on backstepping technique. The MIMO nonaffine system is first transformed into a time-varying system with strict feedback structure using the mean value theorem,and then the bounded time-varying parameters are estimated by adaptive algorithms with projection. To handle the possible"controller singularity" problem caused by unknown control direction, a Nussbaum function is employed, and the dynamic surface control(DSC) method is applied to solve the problem of"explosion of complexity" in backstepping control. It is proved that the proposed control scheme can guarantee that all signals of the closed-loop system are bounded through Lyapunov stability theorem and decoupled backstepping method. Simulation results are presented to illustrate the effectiveness of the proposed control scheme.

Robust H_∞ Stabilization of Uncertain Linear Time-Delay System with Delayed/Undelayed State Feedback Controllers

This paper focuses on the H∞ controller design for linear systems with time-varying delays and norm-bounded parameter perturbations in the system state and control/disturbance. On the existence of delayed/undelayed full state feedback controllers, we present a sufficient condition and give a design method in the form of Riccati equation. The controller can not only stabilize the time-delay system, but also make the H∞ norm of the closed-loop system be less than a given bound. This result practically generalizes the related results in current literature.

Adaptive Server Load Balancing in SDN Using PID Neural Network Controller

Web service applications are increasing tremendously in support of high-level businesses.There must be a need of better server load balancing mechanism for improving the performance of web services in business.Though many load balancing methods exist,there is still a need for sophisticated load bal-ancing mechanism for not letting the clients to get frustrated.In this work,the ser-ver with minimum response time and the server having less traffic volume were selected for the aimed server to process the forthcoming requests.The Servers are probed with adaptive control of time with two thresholds L and U to indicate the status of server load in terms of response time difference as low,medium and high load by the load balancing application.Fetching the real time responses of entire servers in the server farm is a key component of this intelligent Load balancing system.Many Load Balancing schemes are based on the graded thresholds,because the exact information about the networkflux is difficult to obtain.Using two thresholds L and U,it is possible to indicate the load on particular server as low,medium or high depending on the Maximum response time difference of the servers present in the server farm which is below L,between L and U or above U respectively.However,the existing works of load balancing in the server farm incorporatefixed time to measure real time response time,which in general are not optimal for all traffic conditions.Therefore,an algorithm based on Propor-tional Integration and Derivative neural network controller was designed with two thresholds for tuning the timing to probe the server for near optimal perfor-mance.The emulation results has shown a significant gain in the performance by tuning the threshold time.In addition to that,tuning algorithm is implemented in conjunction with Load Balancing scheme which does not tune thefixed time slots.

安全稳定控制系统远程非实时闭环测试技术研究

目前,安全稳定控制系统的测试主要依赖于相互独立的厂内测试、实验室测试和现场联调测试,难以彻底消除安全稳定控制系统潜在的隐患。针对现有测试方法的不足,提出一种安全稳定控制系统远程非实时闭环测试技术。通过融合硬件在环仿真、5G通信组网、广域同步触发、多通信协议转换等关键技术,研发了平台管理系统、测试主站和测试终端等关键模块,并制定了远程非实时闭环测试流程。以四川电网水电经特高压直流集中送出安全稳定控制系统为例,验证了所提技术的可行性。

Red Rice Control and Soybean Tolerance to <i>S</i>-Metolachlor in Association with Glyphosate

Red rice is one of the major troublesome and difficult weeds to control in rice production regions. The introduction of the Clearfield&#174 technology allowed producers to control red rice using rice genotypes tolerant to the imidazolinone herbicides. However, because the consecutive use of this technology red rice biotypes have evolved resistance to imidazolinone herbicides, the rice-soybean rotation has been an alternative used by producers to control this weed. This system allows the use of herbicides with different modes of action to control red rice, such as S-metolachlor. Thus, greenhouse and field experiments were carried out during the 2011 to 2012 and 2012 to 2013 growing seasons to evaluate: 1) sensitivity of imidazolinone-resistant red rice to S-metolachlor;2) red rice control and soybean tolerance in response to associations of S-metolachlor and glyphosate. In greenhouse, S-metolachlor effectively controlled both susceptible and imidazolinone-resistant red rice in preemergence. In field, preemergence applications of S-metolachlor provided greater red rice control in comparison to S-metolachlor alone in early postemergence. The association of S-metolachlor with glyphosate did not improve red rice control in preemergence application. However, association of S-metolachlor with glyphosate significantly improved red rice control in early postemergence applications. S-metolachlor injury to soybean increased with early postemergence applications. These results indicate that S-metolachlor effectively control imidazolinone-resistant red rice in rice-soybean rotation.

法国阿尔斯通公司的Point-on-Wave Controller

本文介绍了大唐韩城第二发电有限责任公司工期2×600 MW工程中采用的国内首次引进法国阿尔斯通公司生产的断路器控制器RPH2的工作原理。以及在不同工况下,如何通过控制断路器各相的分/合闸时间点,来减少断路器正常分/合闸对设备和系统造成冲击。最后介绍了该装置的环境补偿、自适应和负荷电流测量功能。

PID Controller Stabilization for First-order Integral Processes with Time Delay

Due to the widespread application of the PID controller in industrial control systems, it is desirable to know the complete set of all the stabilizing PID controllers for a given plant before the controller design and tuning. In this paper, the stabilization problems of the classical proportional-integral-derivative (PID) controller and the single-parameter PID controller (containing only one adjustable parameter) for integral processes with time delay are investigated, respectively. The complete set of stabilizing parameters of the classical PID controller is determined using a version of the Hermite-Biehler Theorem applicable to quasipolynomials. Since the stabilization problem of the single-parameter PID controller cannot be treated by the Hermite-Biehler Theorem, a simple method called dual-locus diagram is employed to derive the stabilizing range of the single-parameter PID controller. These results provide insight into the tuning of the PID controllers.

The User-defined Modeling Method of Power System Components Based on RTDS-CBuilder

This paper puts forward a method to design the user-defined component based on the user-defined modeling environment CBuilder of RTDS simulator. And also develops the user-defined component model with algorithm described by C language, visual graphics appearance, and the component function. And it generates the dynamic link library which has the same execution efficiency as that of the included model of RTDS. This paper takes the IEEE type EXST1 static excitation system as an example to build the user-defined component. The closed-loop tests on the user-defined component and the included one of RTDS are performed to examine the accuracy of the proposed method. By comparison, the test results show that the external characteristics of the user-defined component and the included model of RTDS are basically the same in the initialization process, the step process of the terminal voltage reference value and the case of the large disturbance.

基于环境参数协同预测风速的掘进面智能变频通风控制系统

针对传统局部风机工况点随掘进巷推进而实时产生偏移的生产安全问题,为研究多环境参数(粉尘浓度、甲烷浓度、温湿度等)对掘进巷风速的影响、探究智能控制技术指导局部风机变频运行的途径,实现对掘进面通风状态的实时监测、协同预测、变频控制,设计了一种掘进面智能变频通风控制系统。基于智能控制理论,采用灰色关联分析算法提取影响掘进巷道需风量的关键因素,以关键因素作为输入层建立了遗传—神经网络风速预测优化模型,开发了组态王上位机监控程序及远程控制界面,并运用S7-200 SMART PLC搭建了基于比例—积分—微分(PID)风量闭环调控技术的掘进面智能变频通风控制系统。研究结果表明:遗传—神经网络风速预测优化模型可根据掘进面不同工况环境参数协同预测风速。智能变频通风控制系统能够通过组态界面实时监测井下掘进面环境参数,还提供自动和手动2种远程控制方式。相比于恒定电源频率调控风机风量,采用PID风量闭环调控技术能远程智能变频控制风机风量,从而使巷道实际风速持续稳定逼近预测值。所研发的智能变频通风控制系统可以广泛应用于不同类型的矿井,实现通风设备自适应调控响应。

玉米–大豆带状复合种植苗前封闭除草药剂筛选

为了筛选适宜在玉米–大豆带状复合种植苗前封闭除草时使用的除草剂,以异丙甲草胺、乙草胺、噻吩磺隆和唑嘧磺草胺为供试药剂,以湘春豆V8(大豆)和登海605(玉米)为供试作物品种,在湖南省邵阳市大祥区台上村开展田间试验,考察各药剂对杂草的防效以及对作物农艺性状、产量和效益等的影响。结果表明:药后30 d,异丙甲草胺+唑嘧磺草胺和乙草胺+唑嘧磺草胺这2个处理对田间杂草的综合防效达80%以上,对常见的苍耳、狗尾草、活血丹等杂草防效达90%以上;药害调查结果表明,供试的除草剂对玉米、大豆幼苗均未产生显著药害,虽然上述2个处理对幼苗株高有一定的影响,但最终并未对产量造成影响,而且纯收入分别比未除草的对照高171.51和176.30元/667m^(2),可以作为玉米–大豆带状复合种植时苗前封闭除草的备选药剂。

The real-time measurement of welding temperature field and closed-loop control of isotherm width

The real-time measurement of welding temperature field by colorimetric method is described, and with the data acquired from it closed-loop control system of the parameters of temperature field is developed and tested. Experimental results prove that it has high measurement speed (time of a field within 0.5s) and good dynamic response quality. Weld penetration can be controlled satisfactorily under unstable welding condition.

气动电磁阀PWM控制可控占空比工作范围的拓宽

某型号气动电磁阀可控占空比范围比较窄,在控制频率10 Hz情况下其为7%~30%。基于上述问题,在分析气动电磁阀工作原理的基础上,基于AMESim搭建气动电磁阀的仿真模型,基于该模型研究了不同占空比对阀芯位移的影响,并通过仿真发现气动电磁阀可控占空比范围比较窄的主要原因是阀芯关闭滞后时间过长。在阀芯关闭时通过增加反向电压,降低电磁阀阀芯关闭滞后时间,并优化反向电压的控制时间,将电磁阀的可控占空比范围提高到5.6%~88.5%,拓宽了占空比的可控范围,并通过试验验证了仿真分析的有效性。

近距离弱冲击煤层群超大孔径瓦斯治理研究

近距离弱冲击松软煤层群掘进期间,常规的瓦斯治理钻孔采用水排渣,塌孔严重。抽采期间钻孔抽采效率差,孔内煤壁塌陷、封堵无法使用,增加了抽采难度。针对该问题采用数值模拟和工程应用实践研究,提出超大孔径一次成孔,高叶片可调速螺旋钻杆旋转排出钻头切割煤屑。针对大埋深近距离煤层群瓦斯,实现同时治理和同步降冲,减少了钻孔施工量,降低了施工成本,瓦斯治理效果显著提升,提供了高效的近距离煤层群掘进期间工作面瓦斯治理的新装备、新工艺。

真空断路器循迹控制

采用带自调整函数的模糊算法,能够使断路器永磁机构按给定曲线动作,保证断路器的合闸时间稳定,从而提高选相操作的精度。通过该算法可实时纠正断路器永磁机构的运动位移偏差,在电容电压、环境温度等外界因素发生变化时,使机构仍按给定曲线动作。通过开关特性测试仪和DSP2812硬件控制系统,得到标准位移曲线及控制算法中的基本参量值,并在Matlab中建立了考虑续流过程的真空断路器闭环控制系统,给出了电容电压变化的仿真结果,验证了上述控制方法的可行性。此外,针对单相配永磁机构真空断路器,进行大量的合闸实验。实验结果表明:在上述外界因素变化时,该控制方法能将断路器合闸时间稳定在±0.5 ms之内。

机插秧稻田二次封闭控草应用技术

稻田草害是机插秧生产中最严重的问题。传统水稻田"一封二杀三补"控草策略策略已经不能适应机插秧的除草要求。本文综合小区试验和大区示范,针对不同栽培条件下的土壤和杂草情况,提出"二封一补"的除草对策。3年试验示范结果表明,土地平整后插秧前使用57%苄·丙·异丙隆可湿性粉剂1 500~1 800 g/hm^2进行第1次封闭处理,插秧后10 d用50%苄·丁·异丙隆可湿性粉剂1 200~1 500 g/hm^2进行第2次封闭,既能有效控制早期杂草为害,保证秧苗安全,又能延长对杂草持续控制作用,提高水稻产量。在2次封闭基础上,针对不平整地块和烤田后抗性杂草发生情况,提出相对应的补治措施。

全数字实时仿真装置与直流输电控制保护装置的闭环仿真方法

介绍了中国电力科学研究院自主研发的电力系统全数字实时仿真装置(advanced digital power system simulator,ADPSS)与直流输电控制保护装置的闭环仿真试验的基本原理、硬件组成和物理接口,并重点阐述了ADPSS与物理装置联合仿真时如何保证数字仿真过程的实时性以及与物理过程同步的解决方法。ADPSS实时仿真的电力系统规模可达1000台机、10000条母线,通过ADPSS与直流输电控制保护装置的闭环仿真,可全面考察装置控制保护策略与大电网动态特性的相互作用,提高对控制保护装置的检测试验水平。

高压断路器液压操动机构特性分析

高压断路器是电力系统的重要控制和保护装置,而液压操动机构是断路器的核心部件之一。液压操动机构具有高压高速大流量性、长期等待性及高可靠性等特点。分析550kVSF6高压断路器液压操动机构的分合闸运动特性,建立电磁铁、高速大流量控制阀和液压缸等仿真模型,对液压机构多级控制阀的响应时间、分合闸速度特性和管路损失等进行仿真分析。讨论管路损失、结构和系统参数等对液压机构特性的影响,并通过试验测试阀腔内油压、液压缸位移速度等特性,证明仿真模型的准确性,为液压操动机构性能的优化提供依据。

脉冲熔化极气体保护焊熔池的视觉传感与实时控制

研究对脉冲熔化极气体保护焊 (GMAW )熔池过程采用视觉传感与实时控制方法的可行性问题。由于GMAW过程的熔滴过渡现象的复杂性 ,尝试模拟焊工通过观察熔池变化等因素来调整焊接参数获取满意的焊缝成形的行为。建立了脉冲GMAW过程熔池视觉传感系统 ,宏观上将熔滴过渡对熔池特征的影响作为黑箱过程处理 ,根据脉冲GMAW弧光光谱分布和熔池图像特征提取 ,实现对脉冲GMAW熔池动态过程的实时检测。采用辨识算法建立焊接动态过程的数学模型 ,进而设计脉冲GMAW熔宽的PID控制器 ,实现对脉冲GMAW熔池宽度的实时控制。试验表明 ,建立的视觉传感系统。

基于dsp和单片机的实时对靶喷施除草系统

根据田间杂草智能喷施系统中图像处理计算量大、实时性要求高、控制任务重的特点,提出了一种基于DSP和单片机相结合的双CPU系统方案,充分利用了DSP实时数据处理能力强和单片机外围控制能力强的优点,实现了系统的快速运算和实时控制功能。同时,介绍了系统的设计方案以及DSP、单片机各自功能的软件实现。试验表明,系统在室内条件下可以满足实时对靶喷施除草的要求。

基于预测函数算法的冷连轧边降滞后控制研究

边降是冷轧带钢控制的重要板形参数之一,它直接影响着带钢的成材率和下游行业产品的质量。目前边降调节的闭环系统中存在严重的滞后问题,解决闭环系统时间滞后问题对于边降控制具有重要意义。传统的滞后控制方法对于高速轧制的冷连轧控制能力很弱,基于此,主要研究预测函数算法对边降闭环控制效果。分析边降板形闭环控制系统中引起反馈信息滞后的主要原因,采用预测函数算法对含有滞后环节的闭环系统进行控制,研究预测函数算法对边降闭环滞后控制的动态特性。仿真结果表明,预测函数算法对于控制模型是否精确具有良好的控制品质,对于外界干扰也具有良好的抗干扰性,除此之外,预测函数具有在线计算量小、适合于高速控制的特性,因而使用预测函数算法可以提高边降板形控制精度。