基于自适应遗传算法的半主动悬架模糊控制研究

模糊规则的正确选择是半主动悬架模糊控制器设计的关键和难点,本文提出一种自适应地选择交叉概率和变异概率的遗传算法,以车身垂直加速度均方根值为优化目标,对汽车半主动悬架模糊控制规则进行优化,以达到提高半主动悬架模糊控制器的控制效果,改善汽车行驶平顺性的目的。为了证明该优化方法的可行性,将该自适应遗传算法优化的模糊控制器对汽车半主动悬架进行控制,并建立Matlab文本与Simulink相结合的仿真模型。仿真结果表明:优化后的半主动悬架车身垂直加速度均方根值减小,汽车行驶的平顺性得到了提高。     

野草入侵模糊算法的半主动空气悬架研究

为了抑制由路面不平引起的车辆振动,结合磁流变阻尼器和空气弹簧的变阻尼/刚度特性,设计了含内置永磁体式磁流变阻尼器的半主动空气悬架系统.基于电磁学原理,对内置永磁体式磁流变阻尼器的力学特性建模.建立了1/4车辆二自由度动力学模型,并利用野草入侵算法对常规模糊算法规则进行优化,开发了野草入侵-模糊混合控制策略对内置永磁体磁流变阻尼器的空气悬架进行半主动控制.为验证该控制策略在磁流变空气悬架的半主动控制效果,进行了C级路面随机输入及凸块脉冲输入仿真分析,仿真结果可知,野草入侵-模糊控制策略能有效地提高半主动悬架系统的综合性能.并且通过台架试验进一步表明,利用该控制策略能够使车身振动加速度及悬架动挠度分别减小25.87%、35.13%.     

基于天棚控制算法的磁流变半主动控制系统的研究

以天棚控制方法为理论基础,结合磁流变减振器的工作机制,建立了磁流变半主动悬架硬件结构系统,并通过在实车试验平台上实验分析了被动悬架和磁流变半主动控制悬架的平顺性。结果表明,相比于被动悬架,磁流变半主动悬架能够很好地抑制低频段车体垂直方向的加速度变化和振动幅值,从而提高车辆平稳性和舒适性。     

列车横向半主动悬挂模糊控制策略研究

针对17自由度列车横向半主动悬挂,提出以横向振动加速度最大值和均方根值作为评价指标,分析了列车横向悬挂模糊控制策略。列车横向半主动悬挂广泛地采用模糊控制调整阻尼值,减少横向振动,提高横向平稳性。因此,利用simulink建立列车横向悬挂模型,设计模糊控制策略直接法和间接法,进行了仿真。仿真结果显示,由于横移和摇头加速度的相互作用,使得前端横向合成加速度大于后端;通过加速度功率谱密度函数值分析对比,直接法综合控制效果好,好于间接法和被动悬挂控制。     

车辆主动悬架的BP神经网络自适应PID控制

提出了一种主动悬架的基于BP神经网络的自适应PID控制方法,并借助于1/4主动悬架物理模型,探讨了该控制技术在车身主动减振方面的控制问题.以白噪声模拟路面输入,对车辆主动悬架系统进行计算机仿真研究.将BP神经网络PID主动悬架、PID主动悬架和被动恳架的车身加速度、悬架动挠度及车轮动位移三项指标的均方根值进行了对比分析.仿真结果表明,具有BP神经网络PID控制器的主动悬架控制效果明显优于PID主动悬架和被动悬架,可大大减少路面对车身的振动冲击,能显著地提高车辆行驶平顺性和乘坐舒适性,且鲁棒性好.     

履带车辆半主动悬架控制系统硬件设计

研究了履带式车辆单轮悬挂模型的车体加速度均方根值特性，提出了一种最优阻尼的控制策略，同时给出了按此控制策略研制的履带式车辆半主动悬架控制系统的硬件设计及其典型特点。经过实际的试验，进一步证实了半主动悬挂系统能有效地减小车体的加速度均方根值，从而提高了车辆平顺性。     

工程车减振系统自适应滤波控制器设计与仿真

对于大吨位和高驶速度的工程车辆,普通减振系统己不能满足车辆振动舒适性的需要,振动控制研究是设计开发新一代工程车辆、提高舒适性的重点问题.针对工程车辆悬架系统的振动特点,为了行驶平顺性和保证系统安全性,提出建立适用于工程车辆振动控制的新型自适应控制器,简化的车辆模型和自适应滤波算法.仿真结果表明,簧载质量加速度的均方根值降低23%,悬架系统动挠度均方根值降低33%,工程车辆的乘坐舒适性得到明显改善,为设计提供可靠依据.     

汽车天棚控制半主动悬架模型仿真与性能分析

该文对比研究了天棚控制半主动悬架的动力学性能。在建立线性被动悬架、传统非线性弹簧悬架和天棚控制半主动悬架动力学模型的基础上。利用MATLAB软件的SIMULINK工具箱对其进行仿真，获得车身加速度时域频域响应特性、轮胎动载荷及悬架动挠度的时域特性，并对仿真结果进行了对比分析。天棚控制半主动悬架的阻尼系数通过估算确定。结果表明。半主动悬架有效地改善了汽车的行驶平顺性和操纵稳定性，但其在衰减高频振动上仍存在不足。     

一种改进的天棚半主动控制算法

针对传统天棚阻尼控制对参数可变的磁流变半主动悬挂系统不能进行有效控制的问题,设计了一种最小控制综合与天棚混合的控制算法;首先建立了理想天棚阻尼控制算法的模型,依据最小控制综合算法模型结构特点将理想天棚阻尼控制作为参考模型;然后依据磁流变阻尼器控制力特点,改进了最小控制综合算法的反馈控制方程,得到混合控制算法的控制律;最后对改进的算法进行了仿真分析;仿真结果表明,混合控制算法在悬挂系统参数发生变化的情况下能够有效降低车体加速度和车轮动载荷,具有较好的控制效果;所设计的改进的天棚半主动控制可以提高车辆的行驶平顺性,对被控系统参数的变化具有良好的适应性,具有较高的实用价值。     

基于计算机仿真的汽车悬架性能参数设计

本文给出一种汽车面向行驶平顺性分析的动力学仿真模型,应用仿真模型对某型号依维柯汽车进行了随机不平路面输入下的汽车悬架系统性能参数优化设计研究,得出了该车悬架系统性能参数优化结果.经该车优化后的道路试验结果表明,优化后的汽车行驶平顺性指标-车身振动加速度均方根值比优化前有较大改善,证明该优化方法对于悬架性能参数优化设计是可行的.     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate