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涡扇发动机的性能退化控制与推力确定分析
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作者 范凯 《科技创新导报》 2019年第23期9-10,共2页
航空涡扇发动机是飞机主要动力供给模块之一,航空涡扇发动机性能控制效果对飞机飞行品质、可靠性造成了直接的影响。因此,本文以航空涡扇发动机性能退化控制为入手点,利用性能退化缓解控制技术,设计了航空涡扇发动机部件级模型,并对其... 航空涡扇发动机是飞机主要动力供给模块之一,航空涡扇发动机性能控制效果对飞机飞行品质、可靠性造成了直接的影响。因此,本文以航空涡扇发动机性能退化控制为入手点,利用性能退化缓解控制技术,设计了航空涡扇发动机部件级模型,并对其进行了仿真试验分析。 展开更多
关键词 涡扇发动机 性能退化控制 推力
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基于性能退化缓解的双发推力匹配控制 被引量:1
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作者 李睿超 郭迎清 《航空工程进展》 CSCD 2015年第1期64-70,共7页
为了解决退化程度不同而导致的双发推力不匹配问题,首先介绍基于发动机性能退化缓解控制的双发推力匹配控制系统(在发动机基准控制系统的基础上添加外围控制回路实现对推力的间接控制,并通过设定双发共同遵循的期望推力减少由于发动机... 为了解决退化程度不同而导致的双发推力不匹配问题,首先介绍基于发动机性能退化缓解控制的双发推力匹配控制系统(在发动机基准控制系统的基础上添加外围控制回路实现对推力的间接控制,并通过设定双发共同遵循的期望推力减少由于发动机退化程度不同造成的双发推力差异),之后对该系统所涉及的推力设定、参数估计、转速指令修正等关键技术进行研究,最后在MATLAB/Simulink环境下进行仿真验证,结果表明:该系统可以在发动机参数限制范围内合理地设定双发共同遵循的期望推力,减少推力差异,满足自动协调双发推力匹配的设计要求。 展开更多
关键词 双发 性能退化缓解控制技术 推力匹配控制 推力设定 参数估计 转速指令修正
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航空发动机性能退化缓解控制技术 被引量:22
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作者 李业波 李秋红 +1 位作者 黄向华 赵永平 《航空动力学报》 EI CAS CSCD 北大核心 2012年第4期930-936,共7页
开展了航空发动机性能退化缓解控制技术的相关研究.性能退化缓解控制通过内环控制转速,外环控制推力,实现了对航空发动机的控制.该控制方式既有传统控制方式的优点,又能像直接推力控制那样实现对推力的直接控制,达到提高发动机控制自主... 开展了航空发动机性能退化缓解控制技术的相关研究.性能退化缓解控制通过内环控制转速,外环控制推力,实现了对航空发动机的控制.该控制方式既有传统控制方式的优点,又能像直接推力控制那样实现对推力的直接控制,达到提高发动机控制自主性的目的.为了验证性能退化缓解控制的有效性,以某型双轴混排涡扇发动机为对象进行了控制系统设计及仿真验证.仿真结果表明了性能退化缓解控制技术的有效性和可行性. 展开更多
关键词 航空发动机 性能退化缓解控制 外环控制 内环控制 推力估计
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PCA-CMAC based machine performance degradation assessment 被引量:3
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作者 张蕾 曹其新 +1 位作者 Jay Lee Frank L. Lewis 《Journal of Southeast University(English Edition)》 EI CAS 2005年第3期299-303,共5页
A principal component analysis-cerebellar model articulation controller (PCA-CMAC) model is proposed for machine performance degradation assessment.PCA is used to feature selection,which eliminates the redundant inf... A principal component analysis-cerebellar model articulation controller (PCA-CMAC) model is proposed for machine performance degradation assessment.PCA is used to feature selection,which eliminates the redundant information among the features from the sensor signals and reduces the dimension of the input to CMAC.CMAC is used to assess degradation states quantitatively based on its local generalization ability.The implementation of the model is presented and the model is applied in a drilling machine to assess the states of the cutting tool. The results show that the model can assess the wear states quantitatively based on the normal state of the cutting tool.The influence of the quantization parameter g and the generalization parameter r in the CMAC model on the assessment results is analyzed.If g is larger,the generalization ability is better,but the difference of degradation states is not obvious.If r is smaller,the different states are distinct,but memory requirements for storing the weights are larger.The principle for selecting two parameters is that the memory storing the weights should be small while the degradation states should be easily distinguished. 展开更多
关键词 principal component analysis cerebellar model articulation controller (CMAC) performancedegradation assessment
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Null Controllability of Some Degenerate Wave Equations 被引量:3
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作者 ZHANG Muming GAO Hang 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2017年第5期1027-1041,共15页
This paper is devoted to a study of the null controllability problems for one-dimensional linear degenerate wave equations through a boundary controller. First, the well-posedness of linear degenerate wave equations i... This paper is devoted to a study of the null controllability problems for one-dimensional linear degenerate wave equations through a boundary controller. First, the well-posedness of linear degenerate wave equations is discussed. Then the null controllability of some degenerate wave equations is established, when a control acts on the non-degenerate boundary. Different from the known controllability results in the case that a control acts on the degenerate boundary, any initial value in state space is controllable in this case. Also, an explicit expression for the controllability time is given. Furthermore, a counterexample on the controllability is given for some other degenerate wave equations. 展开更多
关键词 CONTROLLABILITY degenerate wave equation Fourier expansion observability.
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On the feasibility and efficacy of control traffic protection in software-defined networks 被引量:1
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作者 HU YanNan WANG WenDong +2 位作者 GONG XiangYang QUE XiRong CHENG ShiDuan 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第12期40-58,共19页
Software Defined Networking (SDN) is an emerging networking paradigm that assumes a logically centralized control plane separated from the data plane. Despite all its advantages, separating the control and data plan... Software Defined Networking (SDN) is an emerging networking paradigm that assumes a logically centralized control plane separated from the data plane. Despite all its advantages, separating the control and data planes introduces new challenges regarding resilient communications between the two. That is, disconnec- tions between switches and their controllers could result in substantial packet loss and performance degradation. This paper addresses this challenge by studying the issue of control traffic protection in SDNs with arbitrary numbers of controllers. Specifically, we propose a control traffic protection scheme that combines both local rerouting and constrained reverse path forwarding protections, through which switches can locally react to fail- ures and redirect the control traffic using standby backup forwarding options. Our goal is then to find a set of primary routes for control traffic, called protected control network, where as many switches as possible can benefit from the proposed protection scheme. We formulate the protected control network problem, prove its NP-hardness, and develop an algorithm that reconciles proteetability and performance (e.g., switch-to-control latency). Through extensive simulations based on real topologies, we show that our approach significantly im- proves protectability of control traffic. The results should help further the process of deploying SDN in real-world networks. 展开更多
关键词 software-defined network PROTECTION control traffic RESILIENCE optimization
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