基于专家PID的电镀行车速度控制系统

行车在电镀生产线中承担产品起吊及运转工作,其运行速度稳定性、精确性直接影响电镀生产效率.传统PID算法对大滞后、多扰动且难以建立数学模型的电镀行车自动化系统速度控制效果不佳.本文提出一种基于专家PID的电镀行车速度控制系统.该系统以可编程逻辑控制器为控制核心,根据电镀行车运行要求及工程专家的经验,建立专家控制器规则库,...     

高精度脉冲电镀电源控制系统设计

为满足对脉冲电镀电源控制系统提出的更高要求,兼顾高精度与数字化控制的要求,设计出一套以STM32F107芯片作为控制核心的控制系统。通过STM32F107芯片对PWM信号高精度控制及其他外部信号检测与运算,实现脉冲精确控制、电流检测与调控、对复杂负载自适应调节,提高脉冲电镀电源控制系统的控制精度与转换效率。     

电镀生产流程与参数微机控制系统

为提高镀件的质量、节能降耗,必须实现电镀生产全过程的自动化。为此,研制了“电镀流程与参数微机控制系统”。该系统在控制行车多种流程的同时,还实现了电镀电流、冲击电流、光亮剂、温度等参数的检测与控制。本文在剖析电镀工艺流程基础上,论述了微机控制系统的工作原理、接口电路的设置、顺控式工位信号查询的特点,分析了参数信号的检测、放大、转换等硬件支持电路,给出了系统软件设计框图。     

基于单片机的镀液温度智能控制系统设计

鉴于镀液温度具有时变性、非线性和滞后性等特征,为实现精准监控和实时调节,在常规PID控制器中引入专家控制规则,赋予控制系统自适应、快速响应与实时调节等特性。设计了以单片机为控制核心的镀液温度智能控制系统。仿真结果表明:设计的控制系统能够实现对镀液温度的精准监控和实时调节,控制效果理想。     

电镀电流高精度控制系统的设计与实现

为提高电镀电流的稳定性和精度,提出了一种基于单神经元的电镀电流控制算法。介绍了电镀控制系统,包括主电路和主控制器。主电路为电镀过程提供直流电源,主控制器则确保电镀参数的准确性。以电流调控为主要研究对象,将单神经元控制与PID相结合,设计了一种单神经元PID控制器,其参数可自适应调整,能够适应复杂多变的工作环境。仿真和实验结果表明:电镀电流的控制精度明显提高,该控制系统具有响应速率快、控制输出稳定等优点,有利于提升镀件质量。     

电镀生产工艺参数的可编程逻辑控制系统设计

传统电镀生产线自动化程度低、集成度差、过度依赖人工操作,行车运行的精度和时间都无法保证,严重影响镀件的质量。提出一种电镀生产工艺参数的可编程逻辑控制系统设计,依据电镀生产线的结构、工艺流程和工艺参数,匹配适合电镀生产线的可编程逻辑控制器的硬件结构和软件程序。实验结果证明,设计的自动控制系统可以降低电镀启停时的电流冲击,精确控制行车行走的位置和时间,提高了电镀线的生产效率和产品的合格率。     

基于冗余结构的大功率电镀电源设计

基于冗余结构,采用模块化思路设计出一种大功率电镀电源。由多个分散的模块电源构成并机系统,能根据负载需求灵活配比电源,利用STM32主控芯片和FPGA芯片组成集中控制系统实现均流控制,并利用FPGA芯片保证所有功率模块的同步性。该电镀电源具有成本低、控制精度高、可靠性强等优点,能够满足电镀工艺发展对电镀电源提出的要求。     

基于可编程逻辑控制器的电镀生产线控制系统设计

电镀行车是电镀车间的主要设备,它事关整条电镀生产线的运行。通过将可编程逻辑控制器和变频器结合,减小电机启停时的电流冲击,避免行车定位不准确。该系统主要由硬件和软件两部分组成,可避免传统电镀行车的一些设计缺陷,提高自动化水平。     

电镀生产中的微机控制系统

结合我国电镀生产线的实际情况,论述了各类工业控制计算机在电镀生产中的利弊,简单介绍了一般电镀生产线对控制系统的要求。详细说明了以可编程逻辑控制器为控制中心的自动控制系统,给出了系统的硬件配置,并讲解了其控制原理。此控制系统在实际生产中运行良好,提高了生产效率,降低了劳动强度,并提高了产品质量。     

PCB电镀行车控制系统的设计与实现

设计出一套采用三菱FX2N-80MR型PLC作为控制器的系统,通过程序控制行车及其他器件实现PCB电镀生产过程的自动化控制。介绍了控制系统概况,给出了控制系统的设计思路,并进行了试应用评估。结果表明:系统可靠且运行状况良好,生产效率明显提高,满足预期设计要求。     

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.     

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。     

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.     

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.     

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。     

Generic model control — A case study revisited

The application of the Generic Model Control (GMC) algorithm to the control of an evaporator has been reported recently by Lee et al. (1989). The results of their case study are claimed to demonstrate the superiority of the nonlinear GMC algorithm over conventional techniques including Dynamic Matrix Control. In this note it is shown that for the evaporator example the improved performance arises primarily from the full multivariable and feedforward nature of the control law, rather than from the nonlinear nature of GMC.     

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.