A Sender-Initiated Fuzzy Logic Contrnol Method for Network Load Balancing

In this paper, a sender-initiated protocol is applied which uses fuzzy logic control method to improve computer networks performance by balancing loads among computers. This new model devises sender-initiated protocol for load transfer for load balancing. Groups are formed and every group has a node called a designated representative (DR). During load transferring processes, loads are transferred using the DR in each group to achieve load balancing purposes. The simulation results show that the performance of the protocol proposed is better than the compared conventional method. This protocol is more stable than the method without using the fuzzy logic control.

Fuzzy Logic–Based Scheme for Load Balancing in Grid Services

Load balancing is essential for efficient utilization of resources and enhancing the responsiveness of a computational grid, especially that hosts of services most frequently used, i.e. food, health and nutrition. Various techniques have been developed and applied;each has its own limitations due to the dynamic nature of the grid. Efficient load balancing can be achieved by an effective measure of the node’s/cluster’s utilization. In this paper, as a part of an NSTIP project # 10-INF1381-04 and in order to assess of FAQIH framework ability to support the load balance in a computational grid that hosts of food, health and nutrition inquire services. We detail the design and implementation of a proposed fuzzy-logic-based scheme for dynamic load balancing in grid computing services. The proposed scheme works by using a fuzzy logic inference system which uses some metrics to capture the variability of loads and specifies the state of each node per a cluster. Then, based on the overall nodes’ states, the state of the corresponding cluster will be defined in order to assign the newly arrived inquires such that load balancing among different clusters and nodes is accomplished. Many experiments are conducted to investigate the effectiveness of the proposed fuzzy-logic-based scheme to support the load balance where the results show that the proposed scheme achieves really satisfactory and consistently load balance than of other randomize approaches in grid computing services.

A Receiver-Initiated Approach with Fuzzy Logic Control in Load Balancing

This paper proposes a new approach for load balancing by using receiver-initiated load transfer method. Usually data transfer for load balancing starts from a sender node. This is what called a sender-initiated method. In this paper, instead, a load balancing action starts from a receiver node;the receiver node initiates load balancing for asking a sender node for load transfer. Fuzzy logic control is applied in this approach to avoid using a fixed threshold value in load balancing in ad-hoc networks. Performance for the receiver-initiated approach is evaluated and compared with other load balancing approaches—BID protocol, fuzzy logic sender-initiated algorithm and non-fuzzy (threshold based) receiver-initiated algorithm. The results show that the receiver-initiated approach improves network performance by comparing with the other three.

计及气象因素与分时电价影响的综合能源系统负荷调控策略研究

用能高峰时段,综合能源系统多元负荷受气象因素影响,使其用能需求量短时持续上升,导致供需矛盾加剧;同时,综合能源系统多能耦合转换与蓄放单元的电驱动特点(如冰蓄冷空调、电制冷制冰)致使其用能成本受分时电价影响进一步增加。以供冷季用能高峰时段综合能源系统冷-电供需调控为研究对象,提出一种包含冷负荷需求自身调节与供冷功率主动控制的两阶段递进式调控策略,旨在实现多能供需平衡空间的拓展与用能成本的降低。基于模糊C均值聚类并考虑综合气象因素与分时电价的影响,选取调控时段;在第1阶段构建了温-湿舒适度最佳与冷能需求量最低的多目标负荷调节模型,在第2阶段提出了用能成本最低和运行能耗最小的多目标供冷输出功率主动控制策略;选取某校园综合能源系统实际运行数据进行算例仿真,采用ε-约束法以及多维偏好线性规划方法进行多目标求解,并基于用能舒适度变化的运行能耗、用能成本等指标,对比分析负荷需求在用能高峰时段调控优化前后的效果。结果表明,所提方法在满足用能舒适度的同时,能削减约13%的负荷需求,并降低约1.9%系统用能成本,有效缓解多能供需矛盾,增强系统运行的灵活性。

基于模糊离散粒子群的数据中心负载均衡研究

针对传统数据中心网络流量调度策略可能会引发大象流冲突,从而导致网络链路堵塞和负载不均衡问题,提出了一种模糊逻辑和离散粒子群相结合的数据中心负载均衡机制。该研究充分利用软件定义网络集中控制与全局视图特性,首先基于重定义的离散粒子群优化算法对大象流进行筛选;然后设计了一个基于模糊逻辑的综合评价模型,模型根据候选路径的特定参数生成路径综合评分;最后选择综合评分最高的路径转发大象流。实验结果表明,与其他算法相比,本文算法网络吞吐量提高了3.05%,链路利用率提高了8.82%。

基于智能算法的火电机组变负荷控制策略优化

现有火电机组的AGC(automatic generation control,自动发电控制)系统存在控制精度低、响应速度慢等问题,为满足电力保供要求,引入人工智能算法对火电机组变负荷控制逻辑进行升级优化。对行业内已开展应用的神经网络、模糊控制、智能优化算法、专家系统、模型预测控制等各类智能算法进行特性总结与适用性分析,在此基础上提出利用线性自回归模型修正锅炉、汽轮机主控逻辑的方案,并在某350 MW超临界燃煤机组上进行10%额定出力的变负荷仿真实验,结果表明,智能算法优化后的控制逻辑有利于机组缩短响应时间,减少超调量,提高AGC系统的调节品质。

基于油电混动六旋翼无人机的模糊PID飞行控制策略研究

针对油电混动六旋翼无人机飞行因燃油消耗而产生变载荷,进而导致飞行姿态响应迟钝的现象,设计出结合能量管理的模糊PID(proportion integration differentiation,PID)飞行控制策略。首先,以最大需求功率为2.0 kW、质量为18 kg的油电混动六旋翼无人机为研究对象,建立MATLAB/Simulink模型;其次,利用模糊算法对变载荷的质量和转动惯量进行模糊化-隶属度函数-规则库-反模糊化处理,实时调整PID值,解决姿态响应迟钝的问题;最后,设计阶梯和巡航工况,观测无人机的姿态响应情况。结果表明:燃油消耗会在姿态变动时,对位置偏移产生不利影响;与普通PID相比,提出的飞行控制策略会实时修正不同载荷下的PID参数,当飞行状况改变时,位置峰值偏移量为6 m,稳定性能良好;同时,在偏移修正方面,模糊PID可在20 s内对偏移量进行修正,并且能持续保持现有姿态,表明模糊PID飞行控制策略具有优异的跟随性能。

机械传动系统电加载技术研究

文章主要研究电加载试验台设计方案、控制方式及试验验证技术,采用驱动电机与加载电机进行电功率封闭,通过整流、逆变单元以及可编程逻辑控制器(Programmable Logic Controller,PLC)实现转速和加载功率的无级控制与加载精度要求,并与润滑系统、机械系统实现关联互锁,保证系统运行稳定可靠。通过共直流母线控制方案技术研究,实现能源的回收再利用,降低试验成本。

全媒时代视觉思维下的汽车HMI交互设计研究

随着新媒体、媒介的不断更新,消费者进入全媒体时代,汽车产业也在进行技术更迭与创意革新。新能源汽车近几年在市场占比大幅增加,已在HMI(Human Machine Interface)交互领域做出了巨大改变,智能舱取代了传统繁琐的“车机”操作交互,这种颠覆性的改变影响着人们的驾驶方式和出行体验。基于以人为本的交互设计理念及全媒体下的视觉思维逻辑进化、汽车HMI交互设计、情感共鸣等方面,从手机到汽车实现线性联动,针对如何创造良好的车机交互体验进行深入的分析与探讨,为HMI未来设计提供经验。

某空调系统控制逻辑的设计改进及应用

针对某核电厂空调系统在室外温度降低、系统低负荷工况下出现空调室外机组频繁启停、运行状态偏差报警以及就地启动缺乏逻辑保护的问题,进行了原因分析,并提出改进措施,有效地解决了系统控制逻辑的问题。改进后的系统在低负荷工况下运行稳定,可为同类空调系统控制逻辑设计和改进提供参考。

燃料电池船舶复合供能系统控制策略设计与仿真

针对燃料电池船舶复合供能系统中的燃料电池功率波动问题和储能单元电池荷电状态(State of Charge, SOC)极端分化问题,依据系统拓扑结构,提出基于负载功率频率分解与模糊逻辑控制法相结合的复合供能系统控制策略设计。采用实例仿真验证该设计的优势。结果表明,该设计可有效保持燃料电池输出功率平滑,对储能单元SOC具有良好的均衡控制效果。

Utilizing Stability Index Tracing for Precise Load Buses Identification in Load Shedding Problem

This paper proposes a new approach for suitable load buses identification via stability index tracing in performing corrective load shedding. The proposed identification technique is called the Fast Voltage Stability Index Load Tracing (FVSI-LT). By implementing a power tracing algorithm, a group of major contributors on the stress experienced by a power system is able to be precisely identified by a system operator (SO) based on the traced values of FVSI. To be precise, the traced FVSI via FVSI-LT can be used to form a ranking list indicating the priority of buses committed for shedding purpose. After designing a Fuzzy Inference System (FIS) for deciding the allowable load powers to be shed and performing experiment on IEEE 57-Bus reliability test system (RTS), it is revealed that the ranking list provided by FVSI-LT results to the most consistent improvement in terms of voltage stability and losses minimization.

面向分布式存储的高性能可重构加密方案

全球进入以数字经济为主导的信息社会,数据成为关键生产要素,当今越来越多的数据被收集、处理和存储,分布式存储系统作为一种高效的存储架构在各数据领域得到广泛应用。然而,随着数据存储规模的不断扩大,分布式存储面临着信息泄露、数据破坏等更深层次的安全风险挑战。这些挑战将推动大数据分布式存储安全技术的创新变革,促进了国产密码技术和计算存储技术的融合。针对分布式存储节点数据信息泄露等安全问题,考虑到分布式存储加密性能与灵活性等需求,提出一种动态可重构加密存储解决方案。该方案设计了基于bio映射框架的高性能可重构密码模块,在此基础上构建多个配用不同密码算法的存储池,实现高性能硬盘数据加解密操作和存储池密码算法动态切换,并开发了具有密码算法和密钥远程在线加载功能的密码协议,满足各存储节点可重构密码模块统一管理与便捷安全更新需求,实现基于密码重构技术的数据细粒度加密保护和逻辑安全隔离功能。实验结果表明,该方案对存储数据进行加密保护与安全隔离的性能损耗约10%,可为分布式存储系统达到GB/T 39786-2021《信息安全技术信息系统密码应用基本要求》第三级及以上在设备和计算安全、应用和数据安全等方面提出的密码应用技术要求提供技术途径。

Load Frequency Control of Small Hydropower Plants Using One-Input Fuzzy PI Controller with Linear and Non-Linear Plant Model

This study presents an intelligent approach for load frequency control (LFC) of small hydropower plants (SHPs). The approach which is based on fuzzy logic (FL), takes into account the non-linearity of SHPs—something which is not possible using traditional controllers. Most intelligent methods use two- input fuzzy controllers, but because such controllers are expensive, there is economic interest in the relatively cheaper single-input controllers. A non- linear control model based on one-input fuzzy logic PI (FLPI) controller was developed and applied to control the non-linear SHP. Using MATLAB/Si- mulink SimScape, the SHP was simulated with linear and non-linear plant models. The performance of the FLPI controller was investigated and compared with that of the conventional PI/PID controller. Results show that the settling time for the FLPI controller is about 8 times shorter;while the overshoot is about 15 times smaller compared to the conventional PI/PID controller. Therefore, the FLPI controller performs better than the conventional PI/PID controller not only in meeting the LFC control objective but also in ensuring increased dynamic stability of SHPs.

Block-based logical hierarchical cluster for distributed multimedia architecture on demand server

A structure of logical hierarchical cluster for the distributed multimedia on demand server is proposed. The architecture is mainly composed of the network topology and the resource management of all server nodes. Instead of the physical network hierarchy or the independent management hierarchy, the nodes are organized into a logically hieraxchical cluster according to the multimedia block they caches in the midderware layer. The process of a member joining/leaving or the structure adjustment cooperatively implemented by all members is concerned with decentralized maintenance of the logical cluster hierarchy. As the root of each logically hierarchical cluster is randomly mapped into the system, the logical structure of a multimedia block is dynamically expanded across some regions by the two replication policies in different load state respectively. The local load diversion is applied to fine-tune the load of nodes within a local region but belongs to different logical hierarchies. Guaranteed by the dynamic expansion of a logical structure and the load diversion of a local region, the users always select a closest idle node from the logical hierarchy under the condition of topology integration with resource management.

基于PLC的污泥计重系统开发

为解决污水处理厂现有污泥计重方式存在的准确度不高和自动化程度不够的问题,采用西门子可编程逻辑控制器(PLC)开发了一套污泥计重系统。通过对现有污泥输送设备的程序控制,选用高精度的称重传感器并对采集数据进行滤波处理,得到了准确和稳定的测量结果,满足了基于污泥处置量实现的商业结算对数据质量的要求。该污泥计重系统在实际应用的项目现场经过了超过10 000 h的运行验证,在测量精度和运行可靠性方面均满足了使用方的要求,得到了结算单位的认可。整个系统具有改造成本低、自动化程度高、适用范围广、可靠性高和测量数据准确的特点,为污泥的计重工作提供了一套切实可行的解决方案。

冲压上下料机械手控制系统设计

冲压上下料设备具有两个机械手,可以同步水平右转或左转、垂直上升或下降,实现冲压生产中上料、下料的自动化。文章设计了以可编程逻辑控制器(Programmable Logic Controller,PLC)为核心的机械手控制系统,它包括触摸屏、伺服驱动和气动控制等。系统设有手动和自动两种工作模式。在自动模式下,一个机械手取走加工好的工件并放置在成品区,另一个机械手同步将待加工的工件从送料台上取走并精确放置到工位。该机械手装置已投入实际应用,具有动作精度高且安全性强的优点,既提高了生产效率,又减轻了劳动强度。

基于电力电子辅助式有载分接开关的Sen变压器开关暂态建模与分析

提出了基于电力电子辅助式有载分接开关(OLTC)的Sen变压器(ST)的开关暂态模型,并对切换过程进行了分析,包括基本的开关逻辑、重叠角和分接头短路的影响以及不同功率因数下最佳切换角的选择方法。基于T形等效电路和拉普拉斯变换建立了基于电力电子辅助式OLTC的ST的开关暂态模型。根据电力电子辅助式OLTC的拓扑结构,建立了基本的开关逻辑。分析了重叠角和分接头短路对切换过程的影响。通过对不同功率因数下切换过程的分析给出了最佳切换角的选择方法。借助MATLAB和PSCAD/EMTDC分别进行解析计算和时域仿真,验证了所提开关暂态模型、开关逻辑和最佳切换角选择方法的有效性,并表明可以在一个周期内完成切换。此外,通过切换角可以控制重叠角和短路电流峰值的大小。

电网负荷转供装置转供模式与当值策略实施研究

为保障电网供区间的枢纽变电站稳定运行,负荷转供装置在保障电网可靠稳定中发挥着重要作用。为此,分析区域内稳定控制的电网结构与负荷转供装置的控制方式,综合考虑装置运行元件状态、主备供电的组别方式、转供方式的优先序列等可控判据逻辑,研究双母双分段复杂接线方式下的转供模式。以失效和修复性作为可靠评价指标,提出当值策略可实施方法,为电网运行提供一定程度的参考。

海上石油平台电源管理系统优先脱扣应用实践

某海上石油平台投产初期,电源管理系统(Power Management System,PMS)刚投入运行不久,当平台发电机进行大修后,在将发电机输出主断路器由测试位遥至工作位时,平台出现大功率负载设备脱扣而引发生产关停。为保证平台的安全生产,需在油田正常生产期间对PMS优先脱扣逻辑进行梳理和相关功能测试,排除异常关停原因,发挥PMS的监控和保护功能,为海上油田正常生产期间PMS优先脱扣功能测试提供实践方法。