Parameter estimation of an unstable system with a PID controller in a closed loop configuration

An essential part of the auto-tuning control involves parameter estimation of a suitable low order model. Since a common way to control an unstable system is via a PID controller, there is a growing interest in the application of new PID-based algorithms for the identification task. In this light the relative advantages of two recently published methods are investigated. The first method is based on typical data of the reaction curve and the time delay is measured directly from the initial portion of the curve. The second method utilizes a least-squares algorithm to get an equivalent time delay together with the values of the other parameters. Thus, the obtained time delay approximates not only the true delay but also part of the nonlinear and the higher order dynamics. This is an advantage when a PID auto-tuning is sought. Two examples are provided to demonstrate and compare between the results of the methods.     

基于模糊控制的水泥回转窑控制系统

本文以水泥回转窑的控制为对象,采用模糊控制器来实现控制。阐述了控制器的设计思想,并成功应用于水泥回转窑的控制中,取得了理想的控制效果。     

Decryption of pure-position permutation algorithms

Pure position permutation image encryption algorithms,commonly used as image encryption investigated in this work are unfortunately frail under known-text attack.In view of the weakness of pure position permutation algorithm,we put forward an effective decryption algorithm for all pure-position permutation algorithms.First,a summary of the pure position permutation image encryption algorithms is given by introducing the concept of ergodic matrices.Then,by using probability theory and algebraic principles,the decryption probability of pure-position permutation algorithms is verified theoretically; and then,by defining the operation system of fuzzy ergodic matrices,we improve a specific decryption algorithm.Finally,some simulation results are shown.     

专家式智能自整定PID控制器的研究与实现

专家控制是目前智能控制研究中最为活跃的领域之一.智能控制与常规PID相结合,形成智能PID控制.本文从专家控制的基本原理、典型结构出发,介绍专家式智能PID控制器的研究与实现方法.     

模式识别在化学工程中的应用

运用模糊集理论及模式识别,对催化剂再生活性、流体流型和裂解炉结焦周期的识别,通过对不同距离和贴近度的计算,取得了良好的效果。     

NFOA-BP融合算法及其在焚烧炉温度控制中的应用

污泥焚烧炉温度控制过程中,由于投入污泥块热值不均以及外界环境干扰,传统的PID控制不能快速稳定地将炉温控制在所需范围内。为适应环境变化,实现更高效的炉温控制,提出一种基于NFOA-BP算法的污泥焚烧温度控制方法。该方法将改进型果蝇算法与BP神经网络结合,通过NFOA算法优化神经网络的初始权重和阈值,进而提高神经网络的全局搜索能力。将NFOA-BP算法应用于污泥焚烧炉温度控制系统,与传统PID温度控制系统进行仿真对比实验。结果表明该系统响应平稳、迅速,超调减小,正确率达到95%以上,比传统PID调节方法提高5%左右。     

科技文章里模糊语的功用

模糊语通过其不确定性,在不同的语言环境下,表现出不同的语用功能。简要阐述了模糊语在科技文章中的几个语用功能。     

VSC-HVDC的稳态模型仿真研究

介绍了轻型直流输电(VSC-HVDC)技术的稳态运行特性,针对VSC-HVDC的稳态情况,设计了VSC-HVDC的控制策略,并基于PID控制原理设计了相应的控制器。仿真实验表明,该方法控制效果良好,对于故障情况能有很快的响应且稳定性良好。     

Engineering education on the ‘fuzzy’ front end: a high-technology entrepreneurship model

We have developed a university entrepreneurship program, culminating in a prototype and business plan, with five objectives: (1) value for all academic participants’ (2) introduction to engineering issues for students; (3) refinement of engineering students’ ‘soft’ skills; (4) training for students in creating value out of embryonic ideas; and (5) a genuine entrepreneurship opportunity for students who wish to pursue a start-up company. The framework is disclosed in the context of three case studies. Furthermore, educational outcomes are derived and discussed based on participant evaluations and faculty reflection. Value creation is evaluated in terms of student performance in graduation exams, in external competitions, industrial interest, investment, intellectual property creation, and market intelligence. Finally, factors that add value to or redirect university research are discussed in the context to better serve society.     

FUZZY测度的奇异性与绝对连续性

首先讨TFUZZY测度的奇异性。然后讨论了FUZZY测度的奇异性与绝对连续性的关系，并得：出了一些有趣结论。