The design of distributed control computer systems

The top-down approach in the design of Distributed Control Computer Systems, DCCS, is presented. The starting point of the study is three statements: (i) the design approach should be production process control oriented; (ii) for real time process control applications, computer networks require an efficient communication subsystem, the most important features of which are high reliability and short message transmission times and (iii) recent research has shown that the tools and methodologies used in both computing and control should be complementary to each other in order to solve some of the distributed control computer system/distributed computer control system design problems. The paper contains the design problems of distributed control computer systems, the presentation of the methods and tools for the study and design of the DCCS, the top-down approach in the design of the DCCS, and examples of two design stages.     

A hierarchical expert system for computer process control

This paper reports on the design and implementation of an expert system for computer process control (HESCPC). The complexity of the expertise necessary for computer process control applications requires that the expert system architecture be structured into a hierarchy of classes of specialized experts. The architecture of HESCPC integrates four classes of expert systems: operator/manager companion expert class, control system algorithm design expert class, hardware expert class, and software expert class. The paper is concerned with the design and implementation of the general system architecture, an operator adviser expert for a nuclear power plant and a control system designer expert using a state space feedback approach. Although the design and implementation aspects of all experts are discussed, the emphasis is on the latter.

At this stage of the HESCPC development, the declarative knowledge represented by 423 metarules and 1261 rules is distributed on a hierarchical structure among 20 experts on different levels of the hierarchy which are able to communicate among themselves to solve difficult control problems.

Examples of control system design sessions of linear mono and multivariable systems using feedback state space approach are given. A run time of an operator-adviser data-driven expert system for a nuclear plant is also presented.     

Computer aided control system design applied to milk drying plants

This paper reviews a computer aided control system design facility that has been used to develop a set of control systems that have been implemented on a pilot scale industrial process. The facility caters for a broad range of control situations including those with interactions, time delays and disturbances. Online interactive graphics is used as a design aid for the identification of plant dynamics and for the assessment of control system performance. Control systems may be developed systematically to be structured in a hierarchical configuration on the plant. Particular applications to the plant, an evaporator and a spray drier, are discussed in detail.     

多模型自适应控制系统计算机辅助设计原理研究

本文比较系统地总结了多模型自适应控制内涵的基本概念,其中包括对象参数空间分割、模型定位、模型分类等。应用这些概念,提出了系统的组成结构和控制算法的基本框架,阐述了系统的设计和仿真步骤。     

Fundamentals of Implementing Real-Time Control Applications in Distributed Computer Systems

Automatic control applications are real-time systems which pose stringent requirements on precisely time-triggered synchronized actions and constant end-to-end delays in feedback loops which often constitute multi-rate systems. Motivated by the apparent gap between computer science and automatic control theory, a set of requirements for real-time implementation of control applications is given. A real-time behavioral model for control applications is then presented and exemplified. Important sources and characteristics of time-variations in distributed computer systems are investigated. This illuminates key execution strategies to ensure the required timing behavior. Implications on design and implementation and directions for further work are discussed.     

Distributed multivariable control system design for coal-fired boilers

This paper describes the multivariable characteristics of industrial coal-fired boilers and associated mathematical models, such as combustion model, a water drum level model and a superheated steam model. The purpose of the paper is to design multivariable control systems using multivariable system frequency domain design theory and the Smith-predictor technique. A specific application shows how to design a model-based distributed multivariable control system for coal-fired boilers in a small-scale power station.     

计算机在新型多电机同步系统中的应用

针对造纸、纺织和印染机械传统多电机拖动系统,因数量众多的松紧架同步控制装置而造成故障率高,使用维护不方便和维修工作量大,严重影响生产的问题,研究了变频调速同步原理和方法,研究和设计了采用计算机通过RS-485控制总线控制变频器实现的新型多电机同步调速方案.该方案不用松紧架或张力等传感器,极大地简化了同步拖动控制系统结构,大大地降低了设备成本并极大地提高了系统可靠性和控制管理水平,而且还能节能降耗,提高产品的产量、质量和设备运行的经济效益.     

PLC在电子加速器控制系统中的应用

全面介绍了一个基于可编程控制器的工业用电子加速器控制系统。它的计算机控制系统采用可编程控制器 (PLC)作为核心设备 ,先进的硬件技术和优化的软件设计使整个系统的可靠性、可扩充性和可维护性都大大地加强     

奇异摄动型卡尔曼滤波算法及其在互联电力系统负荷频率控制中的应用

本文讨论了一种大系统实时随机最优控制算法--奇异摄动型卡尔曼滤波的设计问题. 建立了线性定常离散互联电力系统的奇异摄动模型.奇异摄动型卡尔曼滤波每循环一步所需 要的计算时间和内存量会大大减小.文中还考虑了控制增益的计算问题.通过对华北互联电 力系统LFC的仿真证明了其控制效果和奇异摄动型卡尔曼滤波算法的有效性.     

Implementation of Hard Real-Time Embedded Control Systems

Although the domain of hard real-time systems has been thoroughly elaborated in the academic sphere, embedded computer control systems –- being an important component in mechatronic designs –- are seldom dealt with consistently. Often, off-the-shelf computer systems are used, with no guarantee that they will be able to meet the requirements specified. In this paper, a design for embedded control systems is presented. Particularly, the paper deals with the hardware architecture and design details, the operating system, and high-level real-time language support. It is shown how estimates of process run-times necessary for schedulability analysis can be acquired on the basis of deterministic behavior of the hardware platform.     

Microprocessor techniques for energy conservation in computer rooms

Computers, particularly large ones used by finance bodies and government, are heavy users of electricity both to power the computer and to provide the environment recommended by the computer manufacturer. The power used by the environmental control equipment can be higher than that used by the computer itself. Both capital costs and running costs are high. Some cooling plants consume of the order of a megawatt of power. Recently, very expensive systems have been developed to recover waste heat from computers for use elsewhere in buildings either for hot water supplies or for space heating.This approach can only be easily applied to new custom designed installations, whereas in future most computers will be installed in existing buildings. Most heat is available from such systems in the summer when the demand is at a minimum. At best they are a palliative for an energy design which is wrong in concept.This article advocates an integrated approach to the total computer system design where all the factors, including energy consumption, are considered from the outset and their interactions considered. A working example is described designed on these principles which uses a fresh air ventilation system controlled by a microprocessor. Other advantages include automatic condition monitoring of the equipment, improved security and fire protection. The microprocessor-based environment controller is an order of magnitude cheaper, both in capital and running costs, than conventional designs. There is no evidence to suggest that it is less effective, because the computer installations concerned show higher than average reliability.     

工控应用程序的一种仿真调试方法

工控应用程序的完善设计是保证计算机控制系统的性能与可靠性的一个重要措施 ,而仿真调试是使应用程序完善化的一个重要环节。本文讨论数字仿真技术在工控应用程序实验室调试中的应用原理 ,并给出某火电厂减温器计算机控制系统的工控应用程序的仿真调试作为应用示例加以说明     

多采样率数字控制系统综述

本文给出了多采样率数字控制系统的发展和目前研究情况的综述．根据系统中各采样周期之间的关系，多采样率控制系统可以分为输入多采样率控制系统输出多采样率控制系统和广义多采样率控制系统等．它们又分别对应于采用广义保持器、广义采样器和周期时变控制器的数字控制系统．文中对这三类系统的特点和近期研究成果进行了系统的介绍与讨论．由于“因果条件”， 多采样率控制器具有结构约束．本文综述了几类满足这一结构约束的多采样率控制器的设计方法和各类多采样率控制系统．     

永磁直线电机的无模型自适应控制方法研究

将基于全格式线性化的单入单出非线性离散时间系统的无模型学习自适应控制方法应用在永磁直线电机的速度和位置控制中.控制器的设计是无模型的,是直接基于称为拟梯度的向量,拟梯度向量是通过新型参数估计算法,根据给出的永磁直流直线电机运动模型的输入输出信息在线导出的.无模型控制方法非常适用于实际的阶数难以知道或难以辨识,且是时变的非线性系统.实现了系统阶数较高时的有效控制,弥补了经典自适应控制阶数高时在线计算量过大而不能适应于系统快速变化过程的不足.利用Matlab软件进行仿真实验,验证了该方法对电机这种具有不确知动态的非线性系统的稳定性和抑止外部干扰和噪声的有效性和鲁棒性.     

多总线控制系统通用化通信程序框架设计

对应用于控制系统的通用化通信软件的设计方法进行了研究,通过监听任务下移及监听信息上传的技术方法实现了信息监听功能的通用化设计;通过设计通信路径表的方法实现了数据交互的通用性。此处的通信是指控制系统中各软硬件模块的数据交互;通用化特性体现在,这种通信程序可以应用在任何多总线控制系统中,达到一次设计、多个系统使用的目的,便于控制系统的升级。     

On near optimal neural control of multiple-input nonlinear systems

It has been a common consensus that general techniques for stabilization of nonlinear systems are available only for some special classes of nonlinear systems. Control design for nonlinear systems with uncertain components is usually carried out on a per system basis, especially when physical control constraints, and certain control performance measures such as optimum time control are imposed. Elegant adaptive control techniques are difficult to apply to this type of problems. A new neural network based control design is proposed and presented in this paper to deal with a special class of uncertain nonlinear systems with multiple inputs. The desired system dynamics are analyzed and utilized in the process of the proposed intelligent control design. The theoretical results are provided to justify the design procedures. The simulation study is conducted on a second-order bilinear system with two inputs and uncertainties on its parameters. The simulation results indicate that the proposed design approach is effective.     

管道流量泄漏在线监测中的模糊调度设计

针对管道流量泄漏和管网突发性的爆管,以管道流量泄漏为应用对象,将模糊调度设计应用于管道流量泄漏监测中,研究具有模糊截止期的多控制任务的实时调度问题,提出奉献度概念和最大奉献优先（LDF）的调度策略。为了减小因任务间频繁切换造成的系统开销,提出基于抢占阈值的最大奉献优先（TLDF）调度策略。最后通过仿真比较LDF和TLDF两种调度策略,实现具有模糊截止期的控制任务调度,能够减少并均衡控制性能的损失,同时提高系统计算资源的使用率。     

Optimum design of linear multivariate sampled-data control systems†

This paper deals with the optimum design of linear multivariate sampled-data control systems,

Section 2 is concerned with the design of such control systems which are optimum on the basis of deadbeat performance. This design procedure is general and can be applied similarly to any deterministic inputs such as step, ramp, etc.

Section 3 is concerned with such control systems with respect to an integral form performance criterion. It is desired that the performance index takes the form of an integral, especially when the state variables of a control system are continuous with respect to time. For this reason, the minimum integral control is considered here.

The performance limits for such systems optimized for a deterministic input are considered in §4, and some interesting theorems are proved by using the w-transform.     

仿人智能控制的在线学习模型

仿人智能控制是一种基于知识的智能控制,模拟了人的控制经验与技巧。根据以前的研究成果［１］［２］［３］,文章总结了仿人智能控制的智能性、仿人智能控制设计的多模态性,讨论了仿人智能控制在线学习的必要性及其学习内容,提出了一种新颖的仿人智能推理与控制在线学习模型,为仿人智能控制系统的设计提供了理论基础。     

新型分布式全电子计算机联锁系统研究

以联锁机为核心的集中控制方式是目前计算机联锁系统的主流。但其存在风险集中、工程造价较高、系统维护困难等问题。为了进一步提高系统的可靠性、安全性、灵活性,引入区域控制(Field Controller)的概念,将其与分布式控制、智能控制等技术相结合,提出了一种新型的分布式全电子计算机联锁系统结构。以实现进路控制功能为依据建立系统可靠性框图,对其进行定量的可靠性分析及仿真,仿真结果表明系统可保持100000小时可靠运行。以上分析可知:该分布式全电子计算机联锁系统的结构设计合理。