基于现场总线的烟叶复烤控制系统

根据烟叶复烤生产工艺的特点及控制要求，分析并设计了烟叶水分、温度、流量和联锁控制方案；构建了基于Ethernet＋PLC＋Interbus的分布式控制系统。根据控制方案及其控制方式，采用功能图（FBD）编写了PLC控制程序；并利用Citect组态实时监控程序，满足了复烤生产分布式控制要求。该系统在红塔集团复烤车间投入实际运行表明：系统在降低成本、减少维护以及简化操作的同时，极大地提高了烟叶水分控制的精确性、稳定性和实时性，在经济及社会效益方面均取得了良好效果。     

烟厂润叶机电控制系统改造

根据实际润叶生产工艺和控制要求，对红塔烟叶复烤线WF300型润叶机电控系统进行改造，针对原有系统控制精度低，滞后及自动监控不完善提出了新的解决方案，建立了加水前馈一串级控制模型；对加料采用批量控制进行实时修正，上述控制方案利用PLC编程实现，并用CITECT开发实时监控程序实现与PLC的数据交互，完成对生产的实时监控，运行情况表明，改造后该系统控制精度提高、可靠性增强、使用更灵活，更好地满足了润叶工艺质量要求。     

SCADA系统在打叶复烤线上的应用

根据打叶复烤生产线特点及控制要求,采用PC Ethernet PLC INTERBUS构建监控和数据采集(SCADA)系统.对底层现场设备,控制层PLC、上层Citect监控及它们之间的通信方式进行了分析和设计,并开发了监控组态软件和管理程序,实现了对复烤线分布式多点实时监控.     

新型双重控制算法在烟叶复烤过程的应用

针对烟叶复烤过程是一个多干扰、大滞后、不确定的大热容过程,采用传统PID闭环控制无法现达到理想的控制效果,现提出一种新型双重控制算法对烟叶复烤过程的出口水分过程进行控制。区别于主、副回路采用简单PI控制算法的传统双重控制算法,新型双重控制算法在主控制回路中采用预测PI控制算法,使其不仅具有传统双重控制算法的优点而且有效的避免了PI控制算法调节速度慢、波动大的缺点。实际应用证明采用新型双重控制算法可以降低烟叶复烤过程中出口水分的波动幅度,提高了烟叶的合格率和优质率。     

烟叶复烤区温度与排潮率的解耦控制仿真研究

烟叶复烤是香烟生产中的一个重要的环节,复烤过程中温度、水分直接影响了复烤后的烟叶指标和后续烟叶的制丝、打包等工序,复烤干燥区是一个复杂多变量强耦合系统。为了获得较好的控制效果,针对云南某复烤厂仅控制温度而未考虑与湿度的耦合性,并且其控制效果不佳的问题,通过采集大量现场数据,在获得干燥区排潮率软测量模型和温湿度动态模型的基础上,采用前馈解耦控制方法进行了干燥区温度与排潮率的控制仿真研究。仿真研究结果表明,干燥区温度与排潮率的前馈解耦控制与未解耦PID控制相比,具有较好的控制效果。     

烟叶复烤微机控制系统

烟叶复烤微机控制系统的硬件结构、软件设计和控制算法的实现。     

钢板退火炉的PLC仿人模糊控制系统

利用PLC实现钢板退火炉炉温的控制,详细介绍了工艺流程及控制要求、系统硬件配置、控制方案和软件设计.     

基于三菱PLC的烟叶初烤控制器设计

本文主要介绍了烟叶初烤的工艺过程、控制要求和控制原理以及PLC的工作原理和应用。以三菱FX2N系列PLC为核心构成初烤控制器，根据烟叶初烤工艺对干温、湿温的要求，控制器可以自动有效地控制初烤的整个过程，提高了烤烟的质量，降低了烟农的劳动强度。     

干法(IDR)稳定化控制系统设计

介绍了陶瓷级UO2粉末化工转换生产线IDR法稳定化工序的特点及控制系统设计,阐述了该工序的控制要求、联锁要求。据此,给出了该工序的控制方案,并着重探讨了DCS、PLC系统控制方案及比值调节系统的实施,最后总结了设计经验及体会。     

烟叶化学成分采集分析系统的开发

根据配方工艺对烟叶内在质量检测、控制的要求,应用SPC技术,设计了烟叶数据采集、存储、分析流程,开发了烟叶化学成分采集分析系统.系统采用重量控制实现烟箱数据匹配,通过转储程序对配方数据进行集中归档;利用ADO.NET实现了对数据库的检索和配方数据的统计;基于ActiveX控件编程绘制了SPC图,并实现了计算工序能力指数、自动识别数据异常等功能.该系统实现了配方打叶SPC控制,为卷煳配方提供了数据支持.     

E+H组合式过程测控装置及实时监控系统设计

Endress+Hauser(E+H)工业现场仪表广泛应用于石油、冶金、电力、生命科学等多个核心行业,具有可靠集成、精准测量、交互式数据管理等特点.为提高实验装置工业适用性,培养学生熟练运用工业级传感器和过程监控的操作技能,将这类传感器引入实验室,设计了一套E+H组合式过程测控装置与实时监控系统.系统以过程控制涉及的典...     

PKS+TRICON+PLC结构在神华煤制油过程控制中的应用

PKS+TRICON+PLC结构是神华煤制油过程控制中的主导控制结构。对控制系统组态中如何完善软、硬件的组态,提高煤制油过程控制应用水平进行探讨。     

Controllability of time-variant Boolean control networks and its application to Boolean control networks with finite memories

This paper investigates the controllability of time-variant Boolean control networks(BCNs).For the time-variant BCNs,a necessary and sufcient condition for the controllability is given,and a control design algorithm is presented.For a BCN with fnite memories,an equivalent transformation to a time-variant BCN is constructed.Then a necessary and sufcient condition for the controllability and a control design algorithm are obtained.     

Some investigations on fuzzy P + fuzzy I + fuzzy D controller for non-stationary process

The paper addresses the adaptive behaviour of parallel fuzzy proportional plus fuzzy integral plus fuzzy derivative (FP+FI+FD) controller. The parallel FP+FI+FD controller is actually a non-linear adaptive controller whose gain changes continuously with output of the process under control. Two non-stationary processes, whose characteristics change with time, are considered for simulation study. Simulation is performed using software LabVIEW TM . The set-point tracking response of parallel FP+FI+FD is compared with conventional parallel proportional plus integral plus derivative (PID) controller, tuned with the Ziegler-Nichols (Z-N) tuning technique. Simulation results show that conventional PID controller fails to track the set-point and becomes unstable as the process changes its characteristic with time. But the parallel FP+FI+FD controller shows considerably much better set-point tracking response and does not deviate from steady state. Also, a huge spike is observed in the output of PID controller as the reference set-point and process parameters are changed, while the FP+FI+FD controller gives spike free control signal.     

一个反求Bezier曲面控制点的算法

本文将反求m×n次Bezier曲面控制点问题,转化为求解m+1个n+1阶线性方程组和n+1个m+1阶线性方程组问题。这些线性方程组的系数矩阵是著名的Vandermonde矩阵。通过求解Vandermonde矩阵的逆矩阵,使CAD/CAM曲面造型中常常遇到的反求Bezier曲面控制点问题得到有效的解决。同时本文给出了一种求解Vandermonde矩阵的逆矩阵的方法。     

Multi-input sliding mode control of a class of uncertain nonlinearsystems

An effective way to extend to the multi-input case the variable structure control philosophy is based on a set of m+1 control vectors forming a simplex in R^m and on the corresponding switching of the controlled system from one to another of m+1 different structures. Yet, some problems arise when uncertainties are present in certain matrices characterizing the controlled systems. In this paper, conditions are identified under which, even in the presence of uncertainty, the convergence to the sliding manifold is ensured via the application of a multi-input control strategy still based on a simplex of control vectors     

GLIP: A Concurrency Control Protocol for Clipping Indexing

Multidimensional databases are now beginning to be used in a wide range of applications. To meet this fast-growing demand, the R-tree family is being applied to support fast access to multidimensional data, for which the R+-tree exhibits outstanding search performance. In order to support efficient concurrent access in multi-user environments, concurrency control mechanisms for multidimensional indexing have been proposed. However, these mechanisms cannot be directly applied to the R+-tree because an object in the R+-tree may be indexed in multiple leaves. This paper proposes a concurrency control protocol for R-tree variants with object clipping, namely, Granular Locking for clIPping indexing (GLIP), dubbed an R+-tree variant, the Zero-overlap R+-tree (ZR+-tree). To the best of our knowledge, GLIP is the first concurrency control approach designed specifically for the R+-tree and its variants. The proposed GLIP supports efficient concurrent operations on R+-trees with serializable isolation, consistency, and deadlock-free. Experiment results on both real and synthetic data sets validated the effectiveness and efficiency of the proposed concurrent access framework.     

基于网络化控制系统的硬件实验平台构建

构建了基于网络化控制系统的硬件实验平台,使网络化控制系统的研究成果能尽快地得以推广应用。介绍了该硬件实验平台组成结构,它由主控模块、远程数据采集和通信模块、被控对象等3大部分构成。在介绍了各模块的主要功能基础上,阐述了利用Visual C++完成主控模块需要解决的关键问题和初步设计方案,并给出了利用ADCU842和CS8900 实现数据采集和远程通信的硬件结构框图和初步设计方案,基本完成了对硬件实验平台的构建工作。该实验平台提供了硬件实验环境,研究者可以轻松地编写相应算法程序。     

e—B＋树：面向多用户数据库系统优化的索引技术

B^＋树在数据库系统中已成为一种标准的索引结构，其上的并发控制机制对多用户数据库系统的性能有很大的影响．本文提出了一种变种B^＋树──弹性B^＋树－ｅ—B^＋树（ｅｌａｓｔｉｃＢ＋－ｔｒｅｅ），定义了其上的安全点和操作及并发控制方法，对ｅ—B^＋树的重构时机也进行了调整，降低了ｅ—B^＋树上结点的合并／分裂频率，减少了ｅ—B^＋树的维护开销，也缩短了封锁时间，从而使得其上操作的并发度和系统的效率得以提高．     

Stability analysis of constrained MPC applied to discrete-time nonlinear with CLF system

The model predictive control （MPC） strategy with a control Lyapunov function （CLF） as terminal cost is commonly used for its guaranteed stability. In most of the cases, CLF is locally designed, and the region of attraction is limited, especially when under control constraints. In this article, the stability and the region of attraction of constrained MPC that is applied to the discrete-time nonlinear system are explicitly analyzed. The region of feasibility is proposed to substitute the region of attraction, which greatly reduces the calculation burden of terminal constraints inequalities and guarantees the stability of the MPC algorithm. Also, the timevariant terminal weighted factor is proposed to improve the dynamic performance of the close-loop system. Explicit experiments verify the effectiveness and feasibility of the relative conclusions, which provide practically feasible ways to stabilize the unstable and/or fast-dynamic systems.