模糊自适应PID控制算法在纸机烘缸蒸汽系统中的应用

介绍一种模糊自适应PID控制算法及其实现方法.它包含四个部分:①模糊自适应PID参数模型的整定;②模糊逻辑推理及PID参数修正方法;③模糊自适应PID控制算法的实现方法;④系统稳定性分析.该算法能够实现造纸机干燥部烘缸蒸汽温度按设定曲线控制.应用结果表明该算法合理,实现简单,烘缸干燥效果更佳.     

基于自适应模糊PID的注塑机温度控制及仿真

为了对注塑机温度精确控制,针对注塑机温度在传统比例积分微分(PID)控制系统中存在的控制偏差大、调节速度慢等诸多不足的现状,提出将模糊控制器和PID控制器相结合,构造成一个自适应模糊PID控制器,运用MATLAB软件建立传统PID和自适应模糊PID控制器模型,对机筒温度进行仿真对比。设定200℃为给定温度,最终仿真结果显示,与传统PID控制器相比,自适应模糊PID控制器实现了注塑机温度的实时控制,达到了超调量小,升温快速及稳态无误差等要求。表明了自适应模糊PID控制器比传统PID控制器对温度的控制效果更加良好。     

基于模糊自适应PID的回转炉温度控制系统

针对回转炉温度控制的滞后性、强耦合性等特点,设计基于模糊自适应PID控制算法的回转炉温度控制系统。给出系统的结构、工作原理、网络结构与控制器设计方法。Matlab仿真实验结果证明:与传统PID控制相比,基于模糊自适应PID的回转炉温度控制系统具有更好的动态调节性能,满足控制需求。     

基于自适应模糊PID算法的镀液温度控制

鉴于镀液温度具有时变性、非线性和滞后性等特点,为满足电镀生产工艺要求,实现对镀液温度的准确控制,设计了电镀槽液的温度控制系统.采用自适应模糊算法,在线优化PID算法.在Matlab中仿真实验表明,当外界干扰来临时,自适应模糊PID控制算法能快速的整定出最优PID参数,并使系统达到较好的控制效果.实际应用表明:当镀液目标温度为45℃,自适应模糊PID算法具有良好的控温效果,系统运行稳定,稳态精度小于±1℃,可满足电镀工艺要求.     

电镀电流的模糊PID控制算法

为了提高电镀电流的稳定性及抗干扰能力,提出了一种基于模糊PID的电镀电流控制算法。分析了传统PID电镀电流控制算法,并在此基础上引入了模糊控制理论。将模糊控制与PID相结合,根据电镀电流误差及误差变化率对传统PID控制算法中的Kp、Ki、Kd进行自适应调整。仿真和实验结果表明,与传统的PID控制算法相比,模糊PID控制算法具有响应速率快、抗干扰能力强、控制输出稳定等优点,能够显著提高电镀电流品质。     

PVC聚合釜温度自控改造与优化

通过测温装置测得聚合釜内浆料和冷却水出口的实时温度,采用串级PID控制方法控制冷却水流量,从而控制聚合釜内的浆料温度。     

基于模糊控制的温湿度试验系统的研究

针对温湿度试验箱温湿度控制大滞后和强耦合特性,提出在传统PID控制的基础上,结合温湿度模糊自适应PID控制算法和模糊解耦算法来设计模糊温湿度控制器,并对其进行了仿真试验结果,结果表明该方法控制精度高、响应快,能够满足温湿度试验箱温湿度控制的要求。     

PVC聚合釜温度的组合控制方法

针对青岛海晶化工集团公司45m^3PVC聚合釜的特点及其对温度的要求，采用自适应变比例控制，程序控制及串级异相分程等控制方式相结合的组合控制手段对聚合釜的温度进行控制，取得了令人满意的效果。     

模糊自整定PID控制器的设计与仿真

制浆碱回收蒸发工段第一步就是通过蒸汽将黑液进行浓缩,蒸汽的温度控制效果对后续燃烧工段和苛化工段起着举足轻重的作用。主管道蒸汽温度控制通常具有大惯性、大延迟、时变等特性,采用常规的PID控制难以获得满意的控制效果。为此,提出一种模糊自整定PID控制器的串级控制算法,该算法很大程度上提高了主蒸汽温度的控制品质。针对隶属度函数对模糊推理模型的精度影响和控制算法的特点编写了模糊规则,并且根据动态性要求的不同,分两种情况进行比较。仿真表明,模糊自整定PID串级控制算法在整体性能上要优于传统PID串级控制。     

史密斯预估算法在聚合釜温度控制中的应用研究

工业过程中的时滞现象非常普遍,大时滞的存在严重影响了系统的控制效果和稳定性,导致系统的超调变大,调节时间变长,甚至出现振荡和发散。史密斯预估控制是一种有效的时滞补偿方法,它能有效的解决控制系统中控制通道的纯滞后问题,减少超调量并加速调节过程。聚合釜温度被控对象的迟延的特点,本文介绍了一种采用施密斯预估补偿的聚合釜温度控制系统的应用研究,预计结果采用施密斯预估补偿的控制要优于传统的PID控制,能够很好地满足工业聚合釜的控制性能要求。     

On-line multivariable adaptive control of a binary distillation column

An experimental evaluation of the simultaneous control of top and bottom product compositions of a binary distillation column utilizing multi-variable self-tuning control algorithms is presented. The study was carried out using an 8-tray, 22.86 cm diameter methanol–water pilot scale column with continuous capacitance analysis of top product composition and bottom composition analyzed on a 3 minute cycle, by a gas chromatograph. Column control is studied for ±25% step disturbances in feed flow rate. Terminal composition regulation using both ‘positional’ and ‘incremental’ forms of a generalized minimum variance self-tuning control algorithm is compared with that achieved using a conventional digital PI/PID multiloop control strategy.     

模糊控制的现状与工程应用关键问题研究

详细阐述了模糊控制技术的研究现状,包括经典模糊控制、智能模糊控制和复合模糊控制。研究分析了模糊控制技术在工程应用中存在的若干问题,包括模糊控制规则和参数优化问题、强耦合多变量问题和模糊控制稳态精度问题,并根据目前国内外模糊控制技术的研究趋势,指出了模糊控制技术未来的研究方向。     

NONLINEAR MODEL PREDICTIVE CONTROL

Nonlinear Model Predictive Control (NMPC), a strategy for constrained, feedback control of nonlinear processes, has been developed. The algorithm uses a simultaneous solution and optimization approach to determine the open-loop optimal manipulated variable trajectory at each sampling instant. Feedback is incorporated via an estimator, which uses process measurements to infer unmeasured state and disturbance values. These are used by the controller to determine the future optimal control policy. This scheme can be used to control processes described by different kinds of models, such as nonlinear ordinary differential/algebraic equations, partial differential/algebraic equations, integra-differential equations and delay equations. The advantages of the proposed NMPC scheme are demonstrated with the start-up of a non-isothermal, non-adiabatic CSTR with an irreversible, first-order reaction. The set-point corresponds to an open-loop unstable steady state. Comparisons have been made with controllers designed using (1) nonlinear variable transformations, (2) a linear controller tuned using the internal model control approach, and (3) open-loop optimal control. NMPC was able to bring the controlled variable to its set-point quickly and smoothly from a wide variety of initial conditions. Unlike the other controllers, NMPC dealt with constraints in an explicit manner without any degradation in the quality of control. NMPC also demonstrated superior performance in the presence of a moderate amount of error in the model parameters, and the process was brought to its set-point without steady-state offset.     

裂解炉的先进控制

介绍了中国石油大庆石化公司化工一厂乙烯装置GK一Ⅵ型裂解炉的主要控制方案，并结合工艺操作具体说明控制方案的实现过程。     

Two-degree-of-freedom output feedback controllers for nonlinear processes

In this work, a nonlinear output feedback control algorithm is proposed, in the spirit of model-state feedback control. The structure provides state estimates using a process model, the measured output, and the residual between the model output and the measured output. These estimates will track the process states at a rate determined by a set of tunable parameters. An algebraic transformation of the state estimates is incorporated in the control structure to ensure that the input/output gain of the observer matches the model upon which the static state feedback control law is based. The transformed states are then used in the control law. This leads to a controller of minimal order possessing integral action. The control structure is shown to have the same properties as the standard model-state feedback structure. The resulting algorithm is a two-degree of freedom control law, in the sense that the control action is not a function of the error only, but the output and the set point are processed in different ways. Finally, a simulation example using an exothermic CSTR operating at an open-loop unstable steady state is used to demonstrate the closed-loop performance of the proposed method.     

轮胎硫化生产过程的模糊控制

分析轮胎硫化生产过程的特点,建立了硫化罐温度和压力控制的多维模糊控制数学模型,设计了适合该模型的控制算法,并在实际工程中予以实现。实践表明该控制方法具有较好的鲁棒性和较好的控制效果,并具有一定的推广价值。     

Generic model control — A case study

This paper outlines the use of a process model directly in a control algorithm. The process considered, a forced circulation single-stage evaporator, is a nonlinear interacting process. The control strategy employing a process model derived from fundamental mass and energy balances is shown to outperform single loop and predictive control strategies by a significant amount. The control structure is first presented in general form and then specifically applied to this process.     

粗轧控制系统的设计与应用

结合生产实际,对粗轧控制系统进行综合设计。介绍粗轧控制系统的结构,以及粗轧核心APC控制、粗轧RAWC控制和带铜SSC控制的控制思想并给出相应控制算法。     

Two-degree-of-freedom output feedback controllers for discrete-time nonlinear systems

A discrete-time, model-based output feedback control structure for nonlinear processes is developed in the present work. The structure makes use of a closed-loop observer, while at the same time it guarantees that the overall feedback controller possesses integral action. An algebraic transformation is applied on the observer states to insure that the input/output gain of the observer matches the model upon which the static state feedback control law is based. The resulting control algorithm is a two-degree-of-freedom control law, in the sense that the output and the set point are processed in different ways. The control structure is shown not only to have the same properties as the standard model-state feedback structure, but also that it emerges from a model algorithmic control framework. Finally, a simulation example using an exothermic CSTR operating at an open-loop unstable steady state is used to evaluate the closed-loop performance of the proposed method.     

大时滞过程中的智能复合控制方法及应用

针对复杂工业过程中通常存在的大时滞现象,本文介绍了几种智能复合控制方法,并对其应用进行举例说明。