基于时间触发总线的发动机分布式控制系统原型设计

分布式控制具有重量轻、模块化程度高和可靠性高等特点,是未来航空发动机电子控制系统的发展方向之一。基于时间触发总线TTP/C构建了分布式控制原型系统,根据发动机控制需求将系统划分为监控节点和智能节点的架构,制定了集群级和节点级的TTP/C通信协议。基于Simulink模型设计了智能节点应用软件,基于VxWorks设计了监控节点应用软件。经过系统试验,表明基于TTP/C通信总线的分布式原型系统能够满足发动机分布式控制通信要求,具有实时性好、可靠性高的特点。     

基于CAN总线的航空发动机分布式控制系统通信研究

航空发动机控制系统发展趋势是分布式控制系统,基于数据总线的通信技术是分布式控制系统的关键.首先对基于CAN总线的航空发动机分布式控制系统中各节点(FADEC以及智能装置节点)进行了详细设计.然后结合航空发动机分布式控制系统要求设计了CAN通信方案.最后建立了CAN通信验证平台.实验表明设计的通信方案可以满足航空发动机分布式控制系统要求.     

基于CAN总线的航空发动机智能执行机构的设计

分布式控制是未来航空发动机控制系统的重要发展趋势.作为航空发动机分布式控制系统的主要组成部分,提出了一种基于CAN总线的智能执行机构的设计方案,并给出了具体的硬件电路和软件算法.DSP实现智能执行机构的程序控制和自诊断,CAN总线完成发动机中央处理器与DSP的数据交换,步进电机实现精确的自整角机传感器位置控制.实验结果表明,对比目前的发动机执行机构,提出的智能执行机构克服了相位移动明显、误差大、响应速度慢等缺点,取到了良好的控制效果,对提高系统的测量精度及保证航空发动机的控制品质具有重要意义.     

基于分布式控制的航空发动机智能转速传感器

依据航空发动机转速测量原理,提出并设计了一种基于分布式控制的智能转速传感器.分析了转速测量原理和软件采集实现流程,设计了传感器信号组合倍频调理电路与部分数字信号处理器(DSP)外围接口电路,编写了汇编程序.试验结果表明:该智能传感器测量精度高,误差小于0.02%,处理速度快,适用于航空发动机分布式控制试验研究.     

TTP/C协议的关键特性研究

数据总线是构建分布式实时容错系统的关键技术之一,而基于TTA架构定义的TTP/C协议是面向安全关键领域的最新总线规范;首先介绍了TTP/C协议的基本架构和运行机制,然后深入研究了基于Welch-Lynch算法的分布式容错同步时钟、基于GMP的容错一致性策略和上电启动过程等TTP/C协议的关键特性;研究结果表明TTP/C协议具有严格的时间确定性和完备的容错策略,十分适合作为航空、汽车、铁路等安全关键领域的通用底层解决方案。     

基于Zynq的TTP/C总线节点备份与再整合

TTP/C总线节点的备份与故障节点的再整合是提高总线可靠性与实用性的有效方法。参考 TTP/C 总线协议,在自主设计的基于Zynq的TTP/C总线控制器上设计了一种节点备份与再整合的方法,保证节点故障后可以重新整合进入集群,或者启用备份节点来保证集群的正常功能,最后通过试验验证了所设计的节点备份与再整合方法的有效性。     

基于DSP和CAN总线的航空发动机智能位置控制器

作为航空发动机分布式控制系统的主要组成部分,提出了一种基于CAN总线和数字信号处理器(DSP)的智能位置控制器的设计方案,并给出了具体的硬件电路和软件算法。DSP实现智能执行机构的闭环控制和自诊断,CAN总线完成发动机中央处理器与DSP的数据交换。实验结果表明:提出的智能位置控制器取得了良好的控制效果,且对提高系统的测量精度和航空发动机的分布式控制研究具有重要意义。     

基于分布式控制的航空发动机智能温度传感器

提出了一种基于分布式控制,用AD595和TMS320LF2407ADSP构成的航空发动机智能温度传感器。设计了热电偶测温电路、报警电路、显示电路接口并讨论了分布式控制的总线选择。用切比雪夫分段拟合的方法进行了热电偶的非线性校正。实验结果表明,该智能温度传感器结构简单、能够实时报警、准确度较高(相对误差小于1%),适用于航空发动机分布式控制系统。     

一种用于无人机的分布式飞行控制系统设计①

分布式结构已广泛应用于高可靠航空电子设备的设计中。设计了一种基于控制局域网（CAN）的分布式飞行控制计算机,用于在执行飞行任务过程中无人机的飞行控制律解算和系统管理。根据无人机控制的实时性和可靠性需求,提出了一种CAN通信、双端口随机访问存储器（DPRAM）通信和控制任务相互配合的内部通信机制。实验表明根据该通信机制设计的通信方案完全满足无人机控制的实时性和可靠性要求,同时解决了分布式结构引入的数据延时问题。     

基于DSP的时间触发总线设计与实现

网络通信系统是现代航空电子系统以及其他分布式实时容错系统的中枢,基于时间触发架构的网络通信系统是一个重要的发展方向。首先对于TTP/C协议的基本架构以及上电群启动过程,全局时钟同步,容错策略等关键技术进行介绍,然后提出一种基于TTP的时间触发总线协议,并基于DSP实现协议控制器进行时间触发通讯。结果表明时间触发总线具有良好的时间确定性,容错特性以及较高的总线利用率,适用于航空,铁路,汽车等安全关键系统的底层网络通信。     

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