基于遗传算法的偏心支撑结构优化

提出一种遗传算法,确定偏心支撑结构中的最佳连接点及最大侧向屈曲荷载。这种支撑结构常用于地震区,可给予建筑师更多的设计空间。通过非对角线杆件对结构施加偏心,并通过第3根杆件与框架角点相连。设计这种结构时,常反复试验以确定支撑杆件连接点位置,考虑各种参数,如:开口和框架尺寸、支撑杆件的横截面面积及支撑杆件连接点位置。采用传统方法,通过最大侧向屈曲荷载来确定最佳连接点是很难的。以不同框架为例,证明遗传算法的有效性。     

Reliability-Based Optimal Design of Electrical Transmission Towers Using Multi-Objective Genetic Algorithms

Abstract:   A hybrid methodology for performing reliability-based structural optimization of three-dimensional trusses is presented. This hybrid methodology links the search and optimization capabilities of multi-objective genetic algorithms (MOGA) with structural performance information provided by finite element reliability analysis. To highlight the strengths of the proposed methodology, a practical example is presented that concerns optimizing the topology, geometry, and member sizes of electrical transmission towers. The weight and reliability index of a tower are defined as the two objectives used by MOGA to perform Pareto ranking of tower designs. The truss deformation and the member stresses are compared to threshold values to assess the reliability of each tower under wind loading. Importance sampling is used for the reliability analysis. Both the wind pressure and the wind direction are considered as random variables in the analysis. The research results presented demonstrate the benefit of implementing MOGA optimization as an integral part of a reliability-based optimization procedure for three-dimensional trusses.     

利用模糊逻辑和遗传法对高层建筑结构进行主动控制

近年来土木工程结构上采用的主动调谐质量阻尼(ATMD)控制系统开始引起研究者们极大的关注。强调利用遗传法和模糊逻辑(GFLC)的组合作用,在ATMD控制系统的设计和优化措施中选择合适的参数,以使得在地震激励作用下建筑的反应最小化。因此,提出的方法,在处理不可预知的非线性现象方面,具有模糊逻辑控制(FLC)和遗传法(GAs)的双重优势。模型采用剪切型框架,并且在状态空间下解决问题。这种方法被应用在位于伊朗共和国的雷什特城的一个11层高的实际建筑上。从这种控制系统中得到的结果,与采用TMD方案和线性二次调节(LQR)控制方法中得出的结果相对比发现,GAs和FLC的综合使用对减少建筑在地震作用下的反应非常有效。     

高柔结构风振AMD控制模糊神经网络预测算法研究

基于Takagi-Sugeno模型的模糊神经网络的基本理论,建立了模糊神经网络预测模型。该模型结合神经网络控制和预测控制的优点,解决了控制中的时滞问题。研究了基于聚类法产生模糊神经网络预测控制的模糊逻辑系统,该方法便捷地解决了模糊逻辑控制中模糊控制规则基于专家控制策略和经验而无自学习能力的困难。以深圳京基金融中心为算例,利用模糊神经网络预测算法控制结构在风荷载作用下的振动,仿真结果表明,模糊神经网络预测算法能够有效地减小高柔结构加速度响应。     

基于模糊神经网络算法的电梯群控系统

总结了电梯群控系统的特征,研究了模糊神经网络,实现了模糊推理在神经网络结构中的运用。采用BP神经网络优化了群控系统的部分控制参数。并利用仿真将基于模糊神经网络的电梯群控系统与传统电梯群控方法进行比较。     

A Fuzzy Expert System for Damage Assessment Using Genetic Algorithms and Neural Networks

Abstract: An efficient knowledge-acquisition support method is required for improvement and maintenance of the knowledge base in durability evaluation of an RC bridge deck. Such a method is proposed in this paper to automatically acquire fuzzy production rules. This method makes joint use of genetic algorithms and a neural network. Using a neural network as a subsystem, the evaluation function of genetic algorithms can be provided with the weights of the neural network. Introducing a neural network into genetic algorithms, it is possible to acquire new knowledge so that the method is useful when it is difficult to acquire knowledge in the field.     

采用遗传算法双闭环控制的静止无功发生器研究

无功补偿对于现代电力系统的运行与稳定性来说是必不可少的。研究了静止无功发生器(SVG)的工作原理,并在此基础上建立了SVG的标幺值数学模型。给出了一种基于遗传算法的新型控制方法,保证了输出信号的品质。用MATLAB/SIMULINK进行仿真,仿真结果表明该方法能够快速有效地实现系统的动态补偿。     

Hybrid Control of Structures Using Fuzzy Logic

Abstract: This investigation examined the application of control algorithms based on fuzzy logic to a class of hybrid structural control systems. The investigation included both analytical and experimental verification of the fuzzy control algorithm. The objective of the hybrid system under investigation is to obtain an ideal sliding system with perfect base isolation. As the hybrid system approaches the state of ideal isolation, the effects of imperfections, signal noise, uncertainties, modeling errors, and compensation errors start to play a dominant role in the control performance. Fuzzy logic (or fuzzy set theory) provides a simple framework to capture the effects of nonlinearities and uncertainties in a real problem without an explicit model of the plant or controller.
The applicability of this approach was first investigated analytically and then verified using a benchmark experimental model consisting of a 1:4 scale sliding-base isolated system controlled at its base by a servohydraulic actuator with a digital computer to provide the control signal. The fuzzy controller used feedback from either the acceleration of the moving foundation or the force at the interface to produce control forces in a series of shaking-table tests. The results from this study show the feasibility of the implementation of fuzzy logic to highly nonlinear problems.     

基于ANN吸收式冷水机组模型的遗传算法最优控制

文章讨论了吸收式溴化锂冷水机组目前在其系统控制上存在经典控制理论无法解决的问题,所以提出采用人工智能领域的技术来实现它的控制方案,其中结合了遗传算法和神经网络的优点。文章还探讨了如何有效的实现这种结合,并将其运用到实际的模拟控制中,实现最优化控制。同时,分别就可能的最优化控制方案与标准控制方案进行比较,文中给出各种最优化控制方案的性能。     

采用磁流变阻尼器对斜拉桥的半主动模糊控制

介绍了利用磁流变(MR)阻尼器的一种半主动模糊控制方法来增强斜拉桥的抗震性能。传统的半主动控制方法需要一个主要控制器去决定需要的控制力,而且需要一个次控制器通过比较需求控制力和真实的阻尼力来调节MR阻尼器的输入电压。但本文介绍的方法,采用模糊逻辑代替了主次控制器。由于模糊逻辑根据MR阻尼器的反应直接决定其输入电压,因此它提供了一个简单的设计程序,并且可以很容易地在真实结构上实施。利用对地震作用下的斜拉桥的基准控制可以评估此方法的控制性能。模拟结果表明,这种半主动控制方法可以有效地减轻斜拉桥的地震响应,并且成功地提高MR阻尼器系统的性能。     

改进的遗传算法求解固结系数

基于太沙基一维固结理论,根据遗传算法原理,推导了固结系数与固结时间的参数关系,为固结系数的求解提供了一种计算方法。该法避免了图解法的缺陷,消除了时间对数法等计算方法由于需要确定沉降初始值的误差影响。求解中根据生物进化原理,便于计算机数据处理。通过与现有方法比较,发现该方法准确、可靠和简便,可有效消除人为因素,而取得较好的计算结果。     

基于模糊控制的群控系统的研究

1引言 电梯群控系统解决的问题实际上是在变化的环境当中解决电梯的调度问题,使电梯群组的运行效率达到最优。由于电梯的运行本身具有随机行和不确定性,而且电梯的群控系统控制目标又是多样性的,所以导致了采用传统的控制方法难以满足控制要求。而模糊控制是一种基于规则的控制。它直接采用语言型控制规则,出发点是现场操作人员的控制经验或相关专家的知识,     

Motion Control of Adaptive Truss Structures Using Fuzzy Rules

Abstract: This note describes a design of the fuzzy control system for the kinematic maneuvers of an adaptive system consisting of a truss-type structure with several variable-length members. The deformations of the adaptive modules are coordinatively governed by fuzzy controllers according to the distance signals between the endpoint of the structure and the moving target. In addition, an adaptive gain tuning technique is investigated in this study. The advantages of applying adaptive gain tuning on motion control of adaptive truss structures are presented. The simulation results show that the application to this model is effective and can be easily implemented in the microcomputer.     

以溶解氧浓度作为SBR法模糊控制参数

采用ＳＢＲ法处理石油化工废水,根据反应器内有机物降解与溶解氧浓度（ＤＯ０的相关性,提出了以ＤＯ作为ＳＢＲ法的模糊控制参数。通过大量试验,总结出反应实始阶段（８￣１０ｍｉｎ）溶解氧浓度不仅能够间接地反映进水有机物浓度（ＣＯＤ０,而且对整个反应过程都有重要影响。溶解氧的高低主要受曝气量大小控制,因此可根据初邕阶段溶解氧的浓度及变化情况预测进水有机物浓度,进而实现对曝气量的模糊控制。同时,还发现当有机物     

Multiobjective Optimization of Bridge Deck Rehabilitation Using a Genetic Algorithm

The solution methods of multiobjective optimization have undergone constant development over the past three decades. However, the methods available to date are not particularly robust. Because of the complicated relationship between the rehabilitation cost and deterioration degree of infrastructure systems, it is difficult to find a near‐optimal solution using common optimization methods. Since genetic algorithms work with a population of points, they can capture a number of solutions simultaneously and easily incorporate the concept of Pareto optimality. In this paper a simple genetic algorithm with two additional techniques, Pareto optimality ranking and fitness sharing, is implemented for the deck rehabilitation plan of network‐level bridges, aiming to minimize the total rehabilitation cost and deterioration degree. This approach is illustrated by a simple example and then applied to a practical bridge system with a large number of bridges.     

多目标模糊决策技术在冷热源方案选择中的应用

本文讨论了冷热源方案选择的多目标决策方法的初步模型,并对两个实例进行了分析。计算结果表明,根据具体工程的实际情况,客观地选择评价指标及权重系数,此模型对不同方案进行综合评价,得出最佳方案。     

基于遗传算法的空调水系统优化控制研究

提出一种优化控制策略，采用基因遗传优化算法，能够快速准确地获得各控制变量在预测时间内的最优设定值。实时仿真试验表明，该策略与固定设定值的控制方式以及局部层次的优化控制方式相比，能够在满足控制稳定性的前提下最大限度地节约整个空调水系统的总能耗。     

用遗传算法实现污水管网的优化设计

提出用遗传算法优化大中型污水管网的设计,并与节点递归算法相结合,既满足了污水管网系统内部节点的水力衔接,也保证了管网系统的全局优化。遗传算法具有只需目标函数值而无需导数等信息的优点,并能从全局出发对管网水力参数进行优化,达到费用最低的目标。结合中型污水管网的优化设计,确定了遗传算法的运行参数。     

基于优化模糊控制规则的磁流变阻尼减震结构地震反应分析

由于采用半主动控制的磁流变阻尼器减震结构存在非线性和时变等因素,精确数学模型的建立非常困难。模糊控制是一种比较合适的控制方法,但模糊控制的设计易受人类主观经验的影响而不甚完善,致使控制的效果受到影响。本文利用遗传算法提出一种优化模糊控制规则的新的控制算法,并对安装磁流变阻尼器的某3层钢筋混凝土结构进行了数值仿真,比较了无控结构、模糊控制结构及遗传算法优化模糊控制结构在地震作用下顶层的位移和加速度响应。结果表明:与人为经验设计的模糊控制相比,利用遗传算法优化的模糊控制可使结构顶层位移、加速度的控制效果均得到明显提高。     

模糊控制在中央空调系统中的应用

分析传统控制方法在中央空调系统应用中的弊端,介绍模糊控制在中央空调系统的应用.结合中央空调系统的结构组成、运行原理及特点,介绍冷冻水系统、冷却水系统的模糊控制原理,并结合具体工程案例介绍模糊控制应用在中央空调系统的主要设备构成及其功能,分析其节能效果.