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在工业控制的某些重要场所,控制设备的可靠性和安全性要求非常高,通常需要考虑冗余设计。讨论冗余系统的控制要求,介绍了PROFINET工业以太网技术,并提出了一种基于PROFINET的冗余系统软硬件解决方案。 相似文献
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小型D系列风机属于旋转机械,要求控制系统具有较高可靠性。西门子S7-400H硬冗余系统的价格较高,而S7-300单站控制系统的安全性级别又无法满足部分实际应用需求。具有高性价比的S7-300软冗余控制方案则平衡了价格与可靠性之间的矛盾。该文详细分析了西门子公司的软冗余软件包,得出了软冗余的基本原理;并通过软件编程实现了WinCC flexible和主备CPU的冗余连接切换。该方案已应用于某D1500煤气离心压缩机控制实例中,系统的可靠性满足风机安全运行的要求。 相似文献
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为实现矿井提升机的全自动控制和保护,提升其安全性和可靠性,为矿山生产的安全和效率提供保障,提出基于冗余PLC控制的矿井提升机的全自动交流调速系统。该系统通过变频调速实现矿井提升机的全自动无极调速。实践证明,采用冗余PLC控制的矿井提升机调速系统完全可以实现自动化控制与保护,同时还可以有效节能。随着其在工矿中的实际应用,矿井提升机的安全性和使用效率将大幅度提高。 相似文献
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在一台非冗余4自由度并联机床上添加一条具有主动驱动的冗余支链,构造4自由度驱动冗余并联机床,研究其控制策略。基于相应的非冗余并联机床的位置控制,对冗余机床的冗余支链采用力控制方式以控制冗余支链的内力,其他运动支链采用位置控制以保证机床的运动精度。在推导出控制系统传递函数的基础上,分别分析控制系统的稳定性、抗干扰能力和响应性能。最后将位置/力控制方式集成到冗余机床的数控系统中,并进行试验研究。通过机床沿圆形轨迹运动的轮廓误差试验证明此控制方式可以保证冗余并联机床和对应的非冗余机床具有相似的轮廓误差,而且冗余支链减小了非冗余伸缩支链中的间隙,从而证明了冗余支链力控制工程的有效性和可行性。 相似文献
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现场总线系统的发展,对现场设备的安全性和可靠性要求越来越高。单路串行通信的控制方案,相比较传统的点对点连接,回路影响范围大。因此推出了冗余总线通讯模块,对通讯回路进行备份,提高现场使用的可靠性。冗余总线通讯模块采用双路485总线系统,利用专业的Profibus协议处理芯片VPC3+C,实现总线部分的冗余功能。VPC3+C其内部硬件集成了Profibus底层的协议处理功能,在此基础上开发的从站与各大厂家DCS系统兼容性高。 相似文献
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根据生物洁净室负压环境控制的基本要求,利用PLC技术和计算机控制软件实现系统负压梯度的控制,同时结合计算机技术实现压差控制、故障分析、过程监控以及信息化管理,设计了生物负压环境控制系统,保障负压环境的安全可靠运行. 相似文献
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针对数控加工中采用油润真空泵的传统真空吸附装夹系统存在的设备庞大、购置及维护成本高、产品适应性差以及废油废液污染等问题,对传统真空吸附装夹系统进行了改进.通过新型真空发生器的对比选用以及与真空吸附平台的一体化安装,对原真空吸附工作台容积腔进行结构改进,并增加真空度压力监控表等,实现了真空吸附装夹系统的小型化、经济化和实用化改进.经验证,改进后的真空吸附系统吸附压力稳定,产品加工质量合格,满足产品多样化、高效率以及绿色制造需求. 相似文献
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Hamid Reza Shaker 《Journal of Mechanical Science and Technology》2013,27(4):1117-1123
The objective of the methods within the framework of the plug-and-play process control, and particularly fault-tolerant control, is to establish control techniques that guarantee a certain performance through control reconfiguration at the occurrence of faults or changes. These methods cannot be effective without sufficient redundancy in the process. In this paper, a measure for control reconfigurability that reveals the level of redundancy in connection with feedback control is proposed for bilinear systems. The proposed control reconfigurability measure is the extension of its gramian-based analogous counterpart, which has been previously proposed for linear processes. First, the controllability and observability gramians for parameter-varying bilinear systems are introduced, and then the control reconfigurability measure is presented. This measure is calculated for the bilinear models of an electro-hydraulic drive to demonstrate its relevance to redundant actuating capabilities in the models. 相似文献
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为验证聚合物基体在真空环境产生的逸气效应对复合材料尺寸稳定性的影响,对环氧树脂和氰酸脂两种基体的碳纤维复合材料的真空逸气性能进行了试验研究。首先从理论上分析了膨胀系数与逸气系数之间的关系,获得了二者尺寸稳定性存在差异的理论依据。然后设计了能够精确测量尺寸和质量变化的试验组件,按照卫星环境试验条件对多组试验组件进行了3轮真空试验,精确测量了试验前后试验组件的尺寸和质量。试验结果表明:环氧树脂基体和氰酸脂基体的复合材料质损率(TML)分别为0.033%~0.06%和0.014%~0.029%;环氧树脂基体和氰酸脂基体的复合材料尺寸变化量分别为2~8μm和1~3μm。另外,环氧树脂基试件的质量变化约为氰酸脂基的2倍,说明两种材料在真空环境下的尺寸稳定性有差异。 相似文献
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The control system of vertical mixing equipment is a concentrate distributed monitoring system (CDMS). A reliability analysis model was built and its analysis was conducted based on reliability modeling theories such as the graph theory, Markov process, and redundancy theory. Analysis and operational results show that the control system can meet all technical requirements for high energy composite solid propellant manufacturing. The reliability performance of the control system can be considerably improved by adopting a control strategy combined with the hot spared redundancy of the primary system and the cold spared redundancy of the emergent one. The reliability performance of the control system can be also improved by adopting the redundancy strategy or improving the quality of each component and cable of the system. 相似文献
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Mingjin Yang Xiwen Li Shaoping Li Shuzi Yang 《Frontiers of Mechanical Engineering in China》2008,3(2):133-138
The control system of vertical mixing equipment is a concentrate distributed monitoring system (CDMS). A reliability analysis
model was built and its analysis was conducted based on reliability modeling theories such as the graph theory, Markov process,
and redundancy theory. Analysis and operational results show that the control system can meet all technical requirements for
high energy composite solid propellant manufacturing. The reliability performance of the control system can be considerably
improved by adopting a control strategy combined with the hot spared redundancy of the primary system and the cold spared
redundancy of the emergent one. The reliability performance of the control system can be also improved by adopting the redundancy
strategy or improving the quality of each component and cable of the system. 相似文献
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Kenneth Anderson 《ISA transactions》1991,30(4):107-116
Although most control project specifications for modern digital systems include references to redundancy and fault tolerance, little effort usually is expended to analyze the cost additions to the project. Risk assessment applied to a control system most often maximizes reliability without regard to cost, though the additional expense may have no significant justification. On some projects, redundancy is carried to extremes, while other times partial redundancy is added with minimal gain in overall system reliability.
This paper will assist the project engineer in properly analyzing the benefits of redundancy versus the true cost of this capability and the effect this will have on a project. The methodology described attempts to achieve the system's objectives and quantity the requirements that will be placed on system reliability. The emphasis is not on the cost or safety benefits to the process but on the relative cost/benefits associated with different offerings that implement fault tolerant or redundant functions. 相似文献
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为了解决MEMS器件真空封装内部真空度测试难题,提出采用晶振作为传感器来对内部真空度进行测量,设计并研制了一套基于晶振传感的真空度测量系统。通过实验得到:不同晶振的标定曲线不同;晶振在不同温度下所测得的标定曲线也不同;采用晶振的老化实验来筛选晶振;晶振的回标实验证明采用晶振作为传感器来对内部真空度进行测量的方法是可行的。 相似文献
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为了对行波型旋转超声电机在同向负载下的驱动性能进行测试,并研究真空高低温环境对电机驱动性能产生的影响,设计并搭建了一套测试系统,从而实现了对超声电机转速和负载扭矩的测量,并对测试设备采取了控温措施,保证设备在高低温环境下的测试精度不会下降。试验结果表明,利用该系统可获得有效测试数据,得到超声电机在真空高低温环境下的驱动性能曲线,并将其与常温常压环境下的曲线进行比对,可以看到真空高低温环境对超声电机在同向负载下的驱动性能产生了一定影响。本研究成果为超声电机在航天领域的广泛应用奠定了可靠基础。 相似文献
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针对现代水库闸门的自动化需求,设计了基于Allen—Bradly公司Control Logix的水库闸门冗余监控系统。利用以太网和控制网构建了系统的硬件组网方案。在分析Allen~Bradly公司PLC软件编程环境特点的基础上,设计了PLC控制程序,并使用RSView组态软件编制了上位机和触摸屏的控制界面。为保证系统连续安全运行,采用硬件冗余的方式实现冗余控制。实践证明该系统达到了操作方便、性能稳定的控制效果。 相似文献