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大孔径全可动射电望远镜换馈系统设计
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作者 杨凤辉 汪敏 +1 位作者 董亮 施硕彪 《工程设计学报》 CSCD 北大核心 2023年第5期617-625,共9页
为了进一步满足探月工程、深空探测和其他天文观测任务的需求,对设计初期只配置了一个S/X双频馈源的昆明40 m孔径全可动射电望远镜进行升级改造,研制了其换馈系统。在不改变现有天线结构及光路的基础上,拆除了原S/X双频馈源,安装了新的... 为了进一步满足探月工程、深空探测和其他天文观测任务的需求,对设计初期只配置了一个S/X双频馈源的昆明40 m孔径全可动射电望远镜进行升级改造,研制了其换馈系统。在不改变现有天线结构及光路的基础上,拆除了原S/X双频馈源,安装了新的S/X双频馈源,并增加了C频段、Ku频段馈源;给出了换馈系统的详细设计和实施方案,实现了3个馈源间自动快速可靠的切换。对馈源改造之后的天线性能进行了测试,结果表明,天线的主要性能指标有所提升。馈源及换馈系统改造之后,大孔径全可动射电望远镜具有多频段接收能力,能够完成更多频段的天文观测和深空探测任务,提高了望远镜的观测效率和科研产出。 展开更多
关键词 系统 机构 源喇叭 换馈控制 射电望远镜 天线性能
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Delay-dependent robust H∞ control for a class of uncertain switched systems with time delay 被引量:3
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作者 师佳 吴铁军 杜树新 《Journal of Zhejiang University Science》 EI CSCD 2004年第7期841-850,共10页
For linear switched system with both parameter uncertainties and time delay, a delay-dependent sufficient condition for the existence of a new robust H∞ feedback controller was formulated in nonlinear matrix inequali... For linear switched system with both parameter uncertainties and time delay, a delay-dependent sufficient condition for the existence of a new robust H∞ feedback controller was formulated in nonlinear matrix inequalities solvable by an LMI-based iterative algorithm. Compared with the conventional state-feedback controller, the proposed controller can achieve better robust control performance since the delayed state is utilized as additional feedback information and the parameters of the proposed controllers are changed synchronously with the dynamical characteristic of the system. This design method was also extended to the case where only delayed state is available for the controller. The example of balancing an inverted pendulum on a cart demonstrates the effectiveness and applicability of the proposed design methods. 展开更多
关键词 Linear switched systems Robust H∞ control Matrix inequality Time delay
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Feedback control for manipulating magnetization in spin-exchange optical pumping system
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作者 Ke Zhang Jun Li +2 位作者 Min Jiang Nan Zhao XinHua Peng 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2018年第8期27-32,共6页
Control of magnetization plays an important role in the scientific and technological field of manipulating spin systems. In this work, we study the problem of manipulating nuclear magnetization in the spin-exchange op... Control of magnetization plays an important role in the scientific and technological field of manipulating spin systems. In this work, we study the problem of manipulating nuclear magnetization in the spin-exchange optical pumping system, including accelerating the recovery of nuclear polarization and fixing it on a specific desired state. A real-time feedback control strategy is exploited here. We have also done some numerical simulations, with the results clearly demonstrating the effectiveness of our method, that the nuclear magnetization is able to be driven towards the equilibrium state at a much faster speed and also can be stabilized to a target state. We expect that our feedback control method can find applications in gyro experiments. 展开更多
关键词 optical pumping feedback control nuclear magnetic resonance state stabilization
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