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本文概述了分布式并行系统和分布式共享存储器的一般概念,讨论了使用共享对象和可靠广播的并行程序设计模型,最后给出了我们的改进模型。  相似文献   

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基于iCAN协议的CAN-bus分布式控制系统   总被引:2,自引:0,他引:2  
从建立一个分布式控制系统的角度,探讨CAN—bus网络的应用,以及iCAN协议的制定,这是本文的主要内容。  相似文献   

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分布式控制系统的现状及趋势俞文光TheConditionandDevelopmentofDistributedControlSystem¥YuWenguang在70年代中期推出的分布式控制系统DDS(DistributedControlSystem)...  相似文献   

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《软件》2009,(3):4-4
Experion LS是霍尼韦尔最新推出的小型、灵活的集散式控制系统(DOS),在诸多需要典型连续过程控制应用行业,例如特殊化工、制药、食品与饮料以及消费品行业,Experion LS能够管理所有连续过程控制应用、优化批量处理以及顺序控制。  相似文献   

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This paper presents distributed divergence control algorithms for epsilon serializability for both homogeneous and heterogeneous distributed databases. Epsilon serializability allows for more concurrency by permitting non-serializable interleavings of database operations among epsilon transactions. We first present a strict 2-phase locking divergence control algorithm and an optimistic divergence control algorithm for a homogeneous distributed database system, where the local orderings of all the sub-transactions of a distributed epsilon transaction are the same. In such an environment, the total inconsistency of a distributed epsilon transaction is simply the sum of those of all its sub-transactions. We then describe a divergence control algorithm for a heterogeneous distributed database system, where the local orderings of all the sub-transactions of a distributed epsilon transaction may not be the same and the total inconsistency of a distributed epsilon transaction may be greater than the sum of those of all its sub-transactions. As a result, in addition to executing a local divergence control algorithm in each site to maintain the local inconsistency, a global mechanism is needed to take into account the additional inconsistency Recommended by: Meichum Hsu  相似文献   

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Verification of distributed control systems in intelligent manufacturing   总被引:5,自引:0,他引:5  
This paper presents an application of formal methods for validation of flexible manufacturing systems controlled by distributed controllers. A software tool verification environment for distributed applications (VEDA) is developed for modeling and verification of distributed control systems. The tool provides an integrated environment for formal, model-based verification of the execution control of function blocks following the new international standard IEC61499. The modeling is performed in a closed-loop way using manually developed models of plants and automatically generated models of controllers.  相似文献   

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不确定时滞分布参数系统鲁棒控制的LMI方法   总被引:4,自引:0,他引:4  
对常时滞、变时滞的不确定分布参数控制系统,提出了一种与现有的研究分布参数控制系统不同的鲁棒控制方法.该方法通过构造平均Lyapunov函数,利用线性矩阵不等式知识,在只要求系统本身所固有的系数是负定矩阵的条件下,给出了所给的分布参数系统镇定的充分条件.当模型中的时滞为常时滞时,所得的充分条件与时滞无关.当模型中的时滞为变时滞时,所得模型的镇定准则依赖于时滞.此外,该方法与已有方法比较的一个显著优点就是所获得的条件容易检验,因而易于应用.最后举了一个实例以说明该方法的有效性.  相似文献   

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《国际计算机数学杂志》2012,89(7):1591-1601
In this paper, the model predictive control (MPC) is developed for linear time-varying systems with distributed time delay in state. The Chebyshev operational matrices of product, integration and delay are utilized to transform the solution of distributed delay differential equation to the solution of algebraic equations. The Chebyshev functions are also applied to derive approximate solution of finite horizon optimal control problem involved in MPC. The proposed method is simple and computationally advantageous. Illustrative example demonstrates the validity and applicability of the technique.  相似文献   

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A short review of the various problems which arise in connection with the use of asymptotic methods in the optimal control of distributed systems is presented. We consider the cases when the asymptotic analysis comes from the state equation, or from the cost function, or both and also when the state equation is defined in perturbed domains.  相似文献   

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分布式发电系统并网逆变单元输出电流的控制性能直接影响到系统输出的电能质量. 传统PI控制无法消除并网电流(交流)的稳态误差, 但稳态误差存在的根本原因相关文献描述较少. 为了解释其原因, 首先建立了并网电流线性控制模型, 然后通过线性叠加定理和频域分析, 揭示了传统PI控制交流量存在稳态误差的本质, 并提出一种新的PI控制, 即比例反馈积分PFI控制. PFI控制不仅解决了传统并网电流PI控制中存在稳态误差的问题, 而且还 具有直流抑制特性. 此外, 提出的PI控制具有原理简单, 实现方便, 单相三相系统均适用等优点. 和理论分析一致, 仿真结果验证了提出的PI控制的有效性.  相似文献   

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张果  张云生 《控制与决策》2004,19(8):923-926
对于采用现场总线系统控制的复杂对象,应用智能预测控制的方式对其进行分布式控制,将现场总线的特点与智能预测控制方法相结合,使各子系统之间的参数以及控制动作协调一致,以实现对整个系统的优化控制.提出了在现场总线系统中构建该方法的步骤,并给出了一个采用该控制方法获得较好控制效果的具体实例。  相似文献   

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With reference to a distributed context consisting of computers connected by a local area network, we present the organization of a memory management system giving physical support to a uniform, persistent vision of storage according to a single address space paradigm. Our system implements a two‐layer storage hierarchy in which the distributed secondary memory stores the valid data items and the primary memory supports a form of data caching, for fast processor access. The proposed system defines a small, powerful set of operations that allow application programs to exert explicit control over the memory management activities at the levels of physical storage allocation, data migration across the network, and the data movements between the secondary memory and the primary memory. The system, that has been implemented in prototype form, is assessed from a number of viewpoints. We show that the storage requirements of the information for memory management are negligible. Moreover, the number of messages necessary to determine the network location of a given data item is low and independent of both the network size and the past movements of this data item in the distributed storage.Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

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On-chip distributed memory has emerged as a promising memory organization for future many-core systems, since it efficiently exploits memory level parallelism and can lighten off the load on each memory module by providing a comparable number of memory interfaces with on-chip cores. The packet-based memory access model (PDMA) has provided a scalable and flexible solution for distributed memory management, but suffers from complicated and costly on-chip network protocol translation and massive interferences among packets, which leads to unpredictable performance. In this paper we propose a direct distributed memory access (DDMA) model, in which remote memory can be directly accessed by local cores via remote-to-local virtualization, without network protocol translation. From the perspective of local cores, remote memory controllers (MC) can be directly manipulated through accessing the local agent MC, which is responsible for accessing remote memory through high-performance inter-tile communication. We further discuss some detailed architecture supports for the DDMA model, including the memory interface design, work flow and the protocols involved. Simulation results of executing PARSEC benchmarks show that our DDMA architecture outperforms PDMA in terms of both average memory access latency and IPC by 17.8% and 16.6% respectively on average. Besides, DDMA can better manage congested memory traffic, since a reduction of bandwidth in running memory-intensive SPEC2006 workloads only incurs 18.9% performance penalty, compared with 38.3% for PDMA.  相似文献   

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远程分布式电源设备监控系统平台的设计与实现   总被引:1,自引:0,他引:1  
提出了一种基于互联网络的远程分布式电源设备监控系统平台设计与实现技术,系统不仅对分散在不同地点的设备实行统一监控和管理,而且可以根据不同类型的设备,自行定制设备通信协议,提高系统的适应性。着重阐述了其体系结构及数据采集、设备通信协议定制、调控和状态查询等主要功能。结果表明,该系统可以实时、准确、可靠地对分散在不同场地的远程设备实行统一监控和管理。  相似文献   

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