基于观测器的网络切换模糊系统的鲁棒镇定

研究一类系统状态不可测的不确定性网络切换模糊系统的鲁棒镇定问题。考虑单包传输且没有数据包丢失的情况,建立网络切换模糊系统的离散模型,使用切换技术及多Lyapunov函数方法,设计模糊观测器及反馈控制器,并以矩阵不等式的形式给出使系统渐近稳定的条件。最后仿真结果表明方法的有效性。     

模糊PID复合控制在异丙醇精馏过程中的应用

针对异丙醇精馏过程具有非线性、强耦合、大滞后、随机干扰量大,以及难以建立精确数学模型的缺点,提出了一种模糊PID复合串级控制系统设计方案,主调节器由模糊控制器和PID控制器并行结合,采用基于梯形隶属函数的模糊切换完成两种控制器的无扰切换.该系统既能在动态过程中快速调节,又能在稳态过程中准确调节,在某化工厂的实际应用表明...     

参数不确定非线性系统切换控制

针对一类含有不确定参数的非线性系统,基于其参数的不确定范围,设计多个滑模变结构控制器。在此基础上,基于一给定的指标切换函数构造切换控制器。在确保系统Lyapunov稳定性的前提下,被控对象的控制器按照预先设定好的切换条件,在多个控制器之间相互切换,从而极大地改善系统的瞬态响应。以工业机器人手臂为研究对象,针对机器人手臂运动方程构造滑模变结构控制器,并设计以输出误差为自变量的指标切换函数,基于此切换函数构造切换控制器,使机械手的控制器在多个控制器之间进行切换。针对不同的参数变化范围,研究切换控制的有效性。多个仿真实例表明切换控制能极大地改善控制品质。     

钻井试验装置钻压伺服系统的控制器设计

利用电液伺服控制理论和xPC技术建立钻井试验装置钻压伺服系统,系统采用阀控缸实时电液力伺服控制。以钻力模型为控制对象设计一种由PID控制和模糊控制组成的复合控制器。带有前馈补偿的控制器中引入自调整修正因子,采用模糊切换来保证两种控制的平稳过渡,模糊切换的执行区域可通过设定其隶属函数的形状参数加以确定。仿真和实验结果表明:复合控制方法消除了模糊控制的稳态误差,提高了PID控制的响应速度,改善了电液力伺服系统的综合性能,对被控对象参数变化有很强的适应能力。     

基于导向钻井工具的双冗余控制器设计

为了提高导向钻井工具在复杂地质环境下对井下姿态测量的可靠性,设计一套基于导向钻井的双冗余控制器。首先对双冗余控制器技术进行研究建立双冗余控制器模型,然后提出双冗余控制器方案。实验表明双冗余控制器不但能够检测出系统的故障,能够准确的切换主备控制器,极大的提高了系统的可靠性。     

双时滞线性切换正系统的鲁棒L_1控制器设计

设计了一类正系统在任意切换信号下的鲁棒L1控制器。针对一类带有状态时滞和输入时滞的线性切换正系统,基于线性余正Lyapunov-Krasovskii泛函和平均驻留时间理论,推导出在任意切换信号下使系统指数稳定且具有干扰抑制能力γ的充分条件,进一步设计了鲁棒L1控制器,保证系统不仅是指数稳定且具有干扰抑制能力γ。最后通过数值仿真示例证明了控制器的有效性。     

不确定离散线性切换系统的鲁棒控制

利用共同李亚普诺夫函数方法和线性矩阵不等式处理方法,研究了一类含有结构参数不确定性的离散时间切换系统的鲁棒渐近稳定问题。基于凸组合条件,通过各个子系统的状态反馈控制器和相应切换规律的设计,在有限控制器之间进行切换使得该系统是全局渐近稳定的。文中用数学方法证明了该设计方法的有效性,所得结果为线性切换系统的分析提供了更深的视角,有助于控制系统其它性能实现。     

抗生素发酵过程pH值控制策略的研究

通过对抗生素发酵过程pH值控制特性要求的分析和对模糊控制器的结构分析,设计了一个多级开关量控制和模糊控制结合的一种控制器,使得该控制器具有快速跟踪和调节过程无超调的性能,满足了抗生素发酵过程pH值控制的性能要求。该控制器利用模糊决策对两种控制间切换阀值进行自调整,使得该控制器更好地适应不同的对象特性和时变对象。     

软切换控制器在供水控制系统中的应用

讲述软切换控制器在一台大功率变频器拖动多台电机的情况下,当电动机由变频转到工频运行时,软切换控制器的所起到的作用。     

周期计时切换控制器的设计与制作

周期计时切换控制器(简称切换控制器),在工业自控领域里应用非常广泛。它主要用于控制被控对象的相互联锁的两种状态,即按设定的时间周期的相互切换控制。我厂二期工程空压站施工中,随设备带来的无热再生切换控制装置,由于运输不慎而损坏。为应急工程需要,根据生产工艺要求,笔者设计制作了二台切换控制器。经使用效果很好。与WQ-1-6型和MT-1型产品     

多回路网络控制系统的模糊动态调度

本文首先阐述了采样周期对于网络控制系统性能的影响,然后针对多回路网络控制系统中,回路之间争抢网络资源,导致系统性能恶化的情况,在原有EDF调度算法的基础上,提出含有模糊调度器的多回路模糊动态调度算法。该算法根据系统中各回路的误差和误差变化率,利用模糊控制的方法实时调整各回路的优先级,从而实现对网络控制系统的调度。最后,利用TrueTime工具箱建立了包含模糊动态调度器的网络控制系统仿真模型,并将其与无调度器的网络控制系统进行对比。仿真结果表明,本文所设计的多回路模糊动态调度算法能够合理地安排各回路使用网络的先后顺序,具有较好的控制性能。     

模糊PID控制器的发展

将模糊控制技术和PID控制相结合，可克服常规PID控制器的不足，使PID控制器具有参数自适应能力。介绍了模糊控制器和PID控制器间的关系，从一维、二维及三维模糊控制器的输入－输出形式上，以及解析分析角度出发，可以说模糊控制器人本质上讲是一种非线性PID控制器。还总结了模糊PID控制器的结构。模糊PID控制器可分成两大类，一类由参数可变的PID控制器及一个模糊控制器共同构成，模糊控制器用于完成PID参数的在线整定，控制信号仍由PID控制器生成；另一类直接用模糊控制器来构造、实现PID控制功能。分别归纳了这两类控制器的多种结构形式。最后还对模糊PID控制器的发展进行了展望，提出了模糊PID 控制器结构的选择、控制器参数调整及控制器评价标准的确定这几方面是今后工作的重点。     

FUZZY MODELING AND CONTROL OF BATCH BEER FERMENTATION+

Fuzzy reasoning based modeling of heuristic control rules are employed for control of batch beer fermentation. The effect of different types of membership functions, viz., line, triangular and phi membership functions is evaluated for the fuzzy subset. Various fuzzy model based controllers are presented using two approaches, namely simple fuzzy controller of few rules (FCFR) and rigorous fuzzy controller of many rules (FCM R), and also applied for the temperature control of fermenter. Zadeh's logic and Lukasiewicz's logic are adopted for computing the compositional rule of fuzzy logic inference. The results demonstrate that the proposed fuzzy controllers show better performance than the conventional controllers. FCFR approach provides better control performance, but needs optimum tuning or selection of gains for the fuzzy input and output variables, whereas FCMR approach is preferred due to flexibility in the operation of many control rules. Further, FCMR approach is free from optimum tuning or selection of gains for the fuzzy input and output variables.     

Fuzzy control of dyebath pH in exhaust dyeing

In textile exhaust dyeing, the control of dyebath pH is a critical factor in order to achieve optimum colour yield and levelness. Conventional controllers have not proved entirely successful in controlling dyebath pH since it is difficult to develop an exact mathematical model for the dyeing process. One method is to apply fuzzy control to the dyeing process. For the fuzzy controller to operate successfully, it is important to understand how the dyeing system responds to given reference pH/time profiles. A dynamic model for the dyeing process has been developed and this allows the fuzzy controller to be fine-tuned by computer simulation. Results of the control system simulation showed very satisfactory tracking performances of the pH profiles. This provides a starting point for further fine-tuning of the system under practical dyeing conditions.     

模糊自适应PI控制在空调系统中的研究

以空气焓差法试验台空调系统的温度控制系统为具体仿真对象建立了数学模型,该空调系统可以看作是一阶惯性加纯滞后的环节,而且对象的过程参数和时延时间是时变的,传统的PID控制无法获得理想的控制效果。提出了一种无需辨识环节的具有智能的模糊自适应PI的控制算法并将其应用在该空调系统中,该算法对模糊控制和PI控制进行有机结合,根据实际控制经验,通过模糊控制规则对控制回路中PI控制器的参数进行实时整定,并将该控制算法和经过良好整定的PI控制器在空调系统中的控制性能进行比较。仿真结果表明,模糊自适应PI控制提高了系统的鲁棒性、减小了超调量、提高了抗干扰能力、缩短了调整时间。     

Adaptive type-2 fuzzy logic control of a bioreactor

Two adaptive type-2 fuzzy logic controllers with minimum number of rules are developed and compared by simulation for control of a bioreactor in which aerobic alcoholic fermentation for the growth of Saccharomyces cerevisiae takes place. The bioreactor model is characterized by nonlinearity and parameter uncertainty. The first adaptive fuzzy controller is a type-2 fuzzy-neuro-predictive controller (T2FNPC) that combines the capability of type-2 fuzzy logic to handle uncertainties, with the ability of predictive control to predict future plant performance making use of a neural network model of the nonlinear system. The second adaptive fuzzy controller is instead a self-tuning type-2 PI controller, where the output scaling factor is adjusted online by fuzzy rules according to the current trend of the controlled process. The performance of a type-2 fuzzy logic controller with 49 rules is used as reference.     

Control of a nonlinear continuous bioreactor with bifurcation by a type-2 fuzzy logic controller

The object of this paper is the application of a type-2 fuzzy logic controller to a nonlinear system that presents bifurcations. A bifurcation can cause instability in the system or can create new working conditions which, although stable, are unacceptable. The only practical solution for an efficient control is the use of high performance controllers that take into account the uncertainties of the process. A type-2 fuzzy logic controller is tested by simulation on a nonlinear bioreactor system that is characterized by a transcritical bifurcation. Simulation results show the validity of the proposed controllers in preventing the system from reaching bifurcation and instable or undesirable stable conditions.     

ARTIFICIAL NEURAL NETWORKS: PRINCIPLE AND APPLICATION TO MODEL BASED CONTROL OF DRYING SYSTEMS - A REVIEW

This paper reviews the developments in the model based control of drying systems using Artificial Neural Networks (ANNs). Survey of current research works reveals the growing interest in the application of ANN in modeling and control of non-linear, dynamic and time-variant systems. Over 115 articles published in this area are reviewed. All landmark papers are systematically classified in chronological order, in three distinct categories; namely, conventional feedback controllers, model based controllers using conventional methods and model based controllers using ANN for drying process. The principles of ANN are presented in detail. The problems and issues of the drying system and the features of various ANN models are dealt with upto-date. ANN based controllers lead to smoother controller outputs, which would increase actuator life. The paper concludes with suggestions for improving the existing modeling techniques as applied to predicting the performance characteristics of dryers. The hybridization techniques, namely, neural with fuzzy logic and genetic algorithms, presented, provide, directions for pursuing further research for the implementation of appropriate control strategies. The authors opine that the information presented here would be highly beneficial for pursuing research in modeling and control of drying process using ANN     

基于现场总线的PID参数模糊自适应控制器及其应用

针对生产过程中工况变化频繁，扰动剧烈，存在严重时变性的特点，提出一个PID参数模糊自适应控制策略，并将其设计在基于现场总线的控制设备上，并将其用于发电厂复杂控制系统上。     

基于LonWorks的GA优化复合模糊PID控制系统设计

设计了基于LonWorks的复合模糊PID控制系统,分析了该系统的硬件组成和软件实现方案.在控制嚣设计上,改进了传统的模糊PID控制器结构,采用三个子模糊控制器组成一个复合模糊PlD控制器.把过渡时间作为各子模糊控制器的公共输入并采用遗传算法(GA)对复合模糊PID控制器的隶属度函数进行了优化.通过Mstlab仿真表明,该控制器在参数确定上更具客观性,在控制带有大滞后环节和非线性环节的工业对象时响应速度更快、抗干扰能力更强、动态性能更好.