首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5篇
  完全免费   3篇
  自动化技术   8篇
  2014年   1篇
  2011年   1篇
  2009年   2篇
  2006年   2篇
  2004年   1篇
  2000年   1篇
排序方式: 共有8条查询结果,搜索用时 93 毫秒
1
1.
2.
在进行嵌入式系统的开发的过程中,都必须设计出易于操作的人机互动操作界面。完成此工作会占用开发者过多的时间,甚至以失败告终。文中为开发者论述了一款新系统,即嵌入式图形系统μC/GUI。它不仅具有很好的移植性,而且还具有灵活、简洁、高效、可方便剪裁、程序占用空间小等优点,因此在嵌入式系统行业中得到了广泛的应用。为了提高μC/GUI的实时性,在研究了此系统的运行机制之后,设计了一个动态内存分配的方案。此方案在实验中取得了良好的结果,是非常有效的。  相似文献
3.
This paper presents a formal framework for verifying distributed embedded systems. An embedded system is described as a set of concurrent real time functions which communicate through a network of interconnected switches involving messages queues and routing services.In order to allow requirements verification, such a model is then translated into timed automata. However, the complexity inherent in distributed embedded systems often does not allow to apply model checking techniques. Consequently, the paper presents an abstraction-based verification method which consists in abstracting the communication network by end-to-end timed channels. To prove a given safety property φ requires then (1) to prove a set of proof obligations ensuring the correctness of the abstraction step (i.e. the end-to-end channels correctly abstract the network), and (2) to prove φ at the abstract level. The expected advantage of such a method lies in the ability to overcome the combinatorial explosion frequently met when verifying complex systems. This method is illustrated by an avionic case study.  相似文献
4.
We present an approach to static priority preemptive process scheduling for the synthesis of hard real-time distributed embedded systems where communication plays an important role. The communication model is based on a time-triggered protocol. We have developed an analysis for the communication delays with four different message scheduling policies over a time-triggered communication channel. Optimization strategies for the synthesis of communication are developed, and the four approaches to message scheduling are compared using extensive experiments.  相似文献
5.
郭兵  熊光泽 《计算机科学》2000,27(12):101-104
1 引言嵌入式计算机系统(下称嵌入式系统)是实时系统的重要组成部分,其结构紧凑、资源有限,一般由嵌入式微处理器等硬件及其软件(包括实时操作系统RTOS和实时应用程序)组成,具有嵌入性和实时性等特点。它通常以SOC(system on chip)、单片机、单板机、多板式箱体结构、嵌入式PC等形式嵌入到各式各样的设备或大系统(如数字移动电话、路由器、导弹)  相似文献
6.
鲁静  张晶 《计算机工程》2011,37(18):258-259
分析现有PTIDES执行策略调度算法,综合考虑事件的截止期和执行时间,改进传统最小空闲时间优先算法,将空闲时间作为事件调度优先权,提出零空闲时间优先PTIDES调度算法——ZSFPTIDES。实例分析表明,ZSFPTIDES调度算法能避免事件在处理过程中因得不到及时处理而夭折的现象,减小事件的抢占切换率,优化分布实时嵌入式系统的调度性能。  相似文献
7.
The Controller Area Network (CAN) protocol is widely used in low-cost embedded systems. CAN uses “Non Return to Zero” (NRZ) coding and includes a bit-stuffing mechanism. Whilst providing an effective mechanism for clock synchronization, the bit-stuffing mechanism causes the CAN frame length to become (in part) a complex function of the data contents: variations in frame length can have a detrimental impact on the real-time behaviour of systems employing this protocol. In this paper, two software-based mechanisms for reducing the impact of CAN bit stuffing are considered and compared. The first approach considered is a modified version of a technique described elsewhere (e.g. Nolte et al. [T. Nolte, H.A. Hansson, C. Norström, Minimizing CAN response-time jitter by message manipulation, in: Proceedings of the Eighth IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2002), San Jose, California, 2002]). The second approach considered is a form of software bit stuffing (SBS). In both cases, not only the impact on message-length variations is addressed but also the implementation costs (including CPU and memory requirements) involved in creating practical implementation of each technique on a range of appropriate hardware platforms. It is concluded that the SBS technique is more effective in the reduction of message-length variations, but at the cost of an increase in CPU time and memory overheads and a reduction in the available data bandwidth. The choice of the most appropriate technique will, therefore, depend on the application requirements and the available resources.  相似文献
8.
以降低分布式嵌入式系统整体能耗为目标,立足设备属性及其关系,从系统的启动设备集和设备动态供电电压两个方面着手,提出一种基于Agent的自适应能耗管理及其分析方法.在此基础上,给出分布式嵌入式能耗网(DE-Net),并利用DE-Net模型对系统的基本组件进行建模,根据组件间关系形成能耗模型,以刻画系统的执行流程和能耗属性.最后,利用CTL描述系统性质,并借助Petri网的操作语义来验证方法的正确性和有效性.具体实例应用及实验结果表明:该方法能够有效地降低分布式实时系统的能耗,正确描述能耗自适应调整过程,简化建模和分析过程,对开发具有低能耗DES具有重要的理论意义和实用价值.  相似文献
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号