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GENERAL SOLUTION OF STRESS FIELDS IN AN ELECTROSTRICTIVE MATERIAL WITH POINT CHARGE

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GENERAL SOLUTION OF STRESS FIELDS IN AN ELECTROSTRICTIVE MAT...

第三届全国压电和声波理论及器件技术研讨会

作者： Quan JIANG college of Aerospace engineering,nanjing university of aeronautics and astronautics, nanjing 210016,P.R.china college of Civil engineering,Nantong university,Nantong 226007,china Cun-fa GAO college of Aerospace engineering,nanjing university of aeronautics and astronautics,nanjing 210016,china

In this paper,the electroelastic stress fields in an electrostrictive material with point charge are ***,the general solutions for the potential functions of electric fields and stresses are derived for the case of point charge based on analytical continuation *** explicit results are given for the case of whole infinite *** the effect of interaction for the point charge and the perturbation or extra electric fields is *** is found that the stress functions are different from the ones of piezoelectric *** nonlinear effects for the coupling of electric and stress fields should be considered.

关键词： Electrostriction point charge stress field

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风力机振荡翼型动态失速特性的CFD研究

太阳能学报 2010年第3期31卷 367-372页

作者：雷延生周正贵南京航空航天大学能源与动力学院南京210016

为采用CFD方法研究风力机振荡翼型出现的流动动态失速现象,首先依据实验结果,对比分析了Baldwin-Lomax、Johnson-King、K-ωSST、S-A和K-ω5种紊流模型计算结果,结果表明:K-ωSST模型由于考虑到分离流动的非平衡作用,针对动态失速的计... 详细信息

为采用CFD方法研究风力机振荡翼型出现的流动动态失速现象,首先依据实验结果,对比分析了Baldwin-Lomax、Johnson-King、K-ωSST、S-A和K-ω5种紊流模型计算结果,结果表明:K-ωSST模型由于考虑到分离流动的非平衡作用,针对动态失速的计算精度较高。通过对NACA0012翼型振荡运动的流场进行计算,详细分析了振荡运动过程中翼型表面分离涡的形成、放大直至造成翼型失速以及失速区涡结构。

关键词：动态失速 NACA0012翼型 CFD方法 K-ω SST模型

PERFORMANCE EVALUATION OF SEVERAL FUSION APPROACHES FOR CCD/SAR IMAGES

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Chinese Geographical Science 2003年第1期13卷 91-96页

作者： WANG Yan-li, CHEN Zhe(School of automation Science and Electrical engineering, Beijing university of aeronautics and astronautics, Beijing 100083, P. R. china) School of automation Science and Electrical engineering， Beijing university of aeronautics and astronautics， Beijing 100083， P. R. china

Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAR image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAR image fusion approaches are effective.

关键词： image fusion performance evaluation CCD image SAR image

Study on the Physical Isolation Technology in Network

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Study on the Physical Isolation Technology in Network

首届亚洲机械电子学学术会议

作者： Ye Youliang Dai Yong college of Mechanical and Electrical engineering,nanjing university of aeronautics and astronautics,nanjing 210016,china

The physical isolation technology is one of the most important fields in the research of network security. In this article,two technical routes of physical isolation technology are presented and the principle of the GAP Technology is *** a functional framework of physical isolation technology,integrated with other network security technologies,is put forward and,a Supply-Chain Core Database GAP(SCCDB-GAP)model is ***,the author discussed the principle and realization of SCCDB-GAP model,which is based on so-called “wengcheng” database synchronization technology.

关键词： Physical Islation GAP Technology Database Security Supply-chain

Nonlinear Friction Compensation Controller Design for High Precision Flight Simulator

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Nonlinear Friction Compensation Controller Design for High P...

第二十三届中国控制会议

作者： Duan Haibin , Wang Daobo (college of automation engineering, nanjing university of aeronautics & astronautics, nanjing, Jiangsu, 210016, P. R. china)

＜正＞ It is well known that the undesired phenomena caused by friction can lead to overall flight simulator performance degradation or instability. Based on the popular LuGre friction model, a novel nonlinear friction compensation controller for high precision flight simulator is developed in this paper. The proposed Lyapunov function prove robust global convergence of the tracking error. The hardware of the high precision flight simulator is composed of three closed loop: current feedback loop, rate feedback loop and position feedback loop. Modularization design is adopted in the software design of the high precision flight simulator. Simulation results demonstrate the effectiveness and robustness of the proposed nonlinear friction compensation scheme.

关键词： LuGre Friction High Precision Flight Simulator PID Modularization Design

Composite Nonlinear Bilateral Control for Teleoperation Systems With External Disturbances

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IEEE/CAA Journal of Automatica Sinica 2019年第5期6卷 1220-1229页

作者： Zhenhua Zhao Jun Yang Shihua Li Wen-Hua Chen the college of automation engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China the School of automation Southeast UniversityKey Laboratory of Measurement and Control of School of Computer Science and Engineering (CSE)Ministry of EducationNanjing 210096China the Department of Aeronautical and Automotive engineering Loughborough UniversityLoughboroughLE11 3TUUK

This paper presents a new composite nonlinear bilateral control method based on the nonlinear disturbance observer(NDOB) for teleoperation systems with external disturbances. By introducing the estimations of NDOB and systems' nominal nonlinear dynamics into controller design, a NDOB based composite nonlinear bilateral controller is constructed to attenuate the influence of disturbance and uncertain nonlinearities. As compared with the existing bilateral control methods which usually achieve force haptic(i.e., contact force tracking)through a passive way, the newly proposed method has two major merits: 1) asymptotical convergence of both position and force tracking errors is guaranteed;2) disturbance influence on force tracking error dynamics is rejected through the direct feedforward compensation of disturbance estimation. Simulations on a nonlinear teleoperation system are carried out and the results validate the effectiveness of the proposed controller.

关键词： Bilateral control disturbance observer force haptic teleoperation

Dynamic Modeling and Control of TL Power Amplifier Using Controlled Source

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Dynamic Modeling and Control of TL Power Amplifier Using Con...

2009中国控制与决策会议

作者： Jun Wang,Longxiang Xu college of Mechanical and Electrical engineering,nanjing university of aeronautics and astronautics,nanjing 210016,china

＜正＞The accurate closed-loop system model of Three-Level（TL） power amplifier for magnetic bearing was *** TL power amplifier was a nonlinear system and uncertain math model would affect the stability analysis of power *** on the controlled source method,the nonlinear devices were replaced by controlled voltage source or controlled current *** models of left half bridge and right half bridge were *** four modes with TL control strategy were analyzed and the closed-loop system model of TL power amplifier was obtained. Simulation and experimental results were basically the same and confirmed the validity of the proposed *** results show that the deduced model can better reflect the actual control characteristics of TL power amplifier.

关键词： Power amplifier Controlled source Modeling Magnetic bearing

基于CAN总线的分布式无人机实时仿真设备研究

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系统仿真学报 2009年第6期21卷 1587-1590页

作者：张兵陈欣欣欣竑南京航空航天大学自动化学院南京210016

CAN总线在汽车与工业过程控制领域应用广泛,并扩展到航空航天领域。设计了一种基于CAN总线的小型分布式实时仿真设备,用于在外场开展无人机半物理实时飞行仿真试验。根据实时仿真设备对CAN的实时性需求,提出了一种基于时间触发的,并充... 详细信息

CAN总线在汽车与工业过程控制领域应用广泛,并扩展到航空航天领域。设计了一种基于CAN总线的小型分布式实时仿真设备,用于在外场开展无人机半物理实时飞行仿真试验。根据实时仿真设备对CAN的实时性需求,提出了一种基于时间触发的,并充分发挥了CAN本身位仲裁机制优点的CAN总线高层协议。实验表明该协议完全满足实时仿真设备的实时性要求;同时也表明其提高了总线的带宽利用率达80%以上,适合于需要在较短周期内传输大量数据的应用。

关键词： CAN总线时间触发分布式实时仿真设备无人机

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基于Java的分布式测控系统任务调度研究

系统工程与电子技术 2004年第11期26卷 1661-1665页

作者：闫钧华张焕春经亚枝南京航空航天大学自动化学院江苏南京210016

针对分布式测控系统动态任务调度算法,提出了一种任务迁移的方法。该方法基于Java的对象序列化机制、多线程机制、远程方法调用(remotemethodinvocation,RMI)技术,实现了将重载机上的任务迁移至轻载机上执行。任务迁移的成功使分布式测... 详细信息

针对分布式测控系统动态任务调度算法,提出了一种任务迁移的方法。该方法基于Java的对象序列化机制、多线程机制、远程方法调用(remotemethodinvocation,RMI)技术,实现了将重载机上的任务迁移至轻载机上执行。任务迁移的成功使分布式测控系统动态任务调度算法顺利实现,从而有效地提高了系统效率,达到了负载均衡的目标。详细介绍了任务迁移的实现。

关键词：分布式测控系统动态任务调度任务迁移远程方法调用