动态鲁棒补偿及其在改善跟踪伺服系统低速跟踪性能中的仿真验证

介绍了一种动态鲁棒补偿器的实现原理,并将其用来改善跟踪伺服系统的低速跟踪性能,仿真结果验证了该方法的有效性.     

基于分散化神经鲁棒控制的轨迹跟踪算法研究

针对外部扰动以及建模误差对机械臂轨迹跟踪精度影响的问题,利用递归神经网络设计了分散化的神经鲁棒控制器,采用机械臂各个关节状态方程的子系统表示整个系统。使用滤错训练算法估计神经网络未知权重系数,同时引入鲁棒项抑制关节神经控制器之间的相互影响和建模误差,并利用Lyapunov函数进行稳定性证明。与没有鲁棒项的仿真结果对比表明,设计的分散化神经鲁棒控制器具有更精确的轨迹跟踪精度,误差的收敛性更好,稳定性更高。     

基于模型参考的直线伺服系统离散滑模控制

针对永磁直线同步电机伺服系统存在的诸多不确定性问题,设计了模型参考离散滑模（MRDSMC）位置跟踪控制器。将伺服问题转化为调节问题,为了保证跟踪的快速性,在传统DSMC滑模面的基础上,引入遗忘因子。并采用一步延迟扰动近似来补偿未知扰动。此外,为了抑制由高频未建模动态引起的抖振,在MRDSMC设计中加入低通滤波器。仿真结果表明,该方案能有效地抑制系统未建模动特性的影响,具有很强的鲁棒跟踪性能。     

制导炮弹非线性鲁棒自适应控制系统设计

针对制导炮弹非线性模型存在参数不确定性、建模误差和外界干扰的特点, 基于动态面设计了制导炮弹的鲁棒自适应控制器, 在设计过程中加入了一阶低通滤波器, 得到虚拟控制量的微分, 从而消除传统反步法中“计算膨胀”的难题。针对模型的不确定参数的影响采用鲁棒函数抵消, 并通过非线性阻尼项消除外界扰动, 最后由Lyapunov方法证明该闭环系统为半全局稳定。该设计方法较为简单, 在有效利用已知信息的前提下, 放宽了不确定项的限制条件, 且跟踪误差可以通过控制器的可调参数加以调整。仿真结果证明了该方法的有效性。     

基于FDO非线性预测方法的翼伞航迹跟踪控制

在翼伞系统的状态空间模型的基础上,分析了翼伞的归航轨迹,给出翼伞轨迹跟踪控制问题的数学描述.针对翼伞归航飞行过程中,受到较大的外干扰及不确定性影响,提出基于模糊干扰观测器(FDO)的非线性预测控制策略,设计了翼伞归航系统航迹跟踪控制器.通过仿真试验,表明该飞控系统具有良好鲁棒特性和抗干扰特性.     

一类时变输入时滞不确定系统的鲁棒控制器设计

针对一类具有时变输入时滞的不确定系统,基于Lyapunov-Krasovskii方法,讨论了该类系统鲁棒控制器的设计问题.在不确定性满足范数有界条件下,给出了时滞相关的鲁棒可镇定充分条件及相应的鲁棒控制器设计方法,利用辅助变量和广义状态证明了闭环系统的渐近稳定性.最后,进行了数值仿真,结果证明了该方法的有效性和优越性.     

基于自适应深度稀疏网络的在线跟踪算法

视觉跟踪中,高效鲁棒的特征表达是解决复杂环境下跟踪漂移问题的关键。该文针对深层网络预训练复杂费时及单网络跟踪易漂移的问题,在粒子滤波框架下,提出一种基于自适应深度稀疏网络的在线跟踪算法。该算法利用ReLU激活函数,针对不同类型目标构建了一种具有自适应选择性的深度稀疏网络结构,仅通过有限标签样本的在线训练,就可得到鲁棒的跟踪网络。实验数据表明：与当前主流的跟踪算法相比,该算法的平均跟踪成功率和精度均为最好,且与同样基于深度学习的DLT算法相比分别提高了20.64%和17.72%。在光照变化、相似背景等复杂环境下,该算法表现出了良好的鲁棒性,能够有效地解决跟踪漂移问题。     

基于鲁棒积分的四旋翼飞行器姿态控制

针对四旋翼飞行器姿态控制过程中广泛存在的外部干扰和参数不确定性,提出了一种基于鲁棒符号误差积分(RISE)的四旋翼姿态控制策略。通过一个模型前馈控制项实现精确的模型补偿,抵消模型非线性影响,以及一个鲁棒积分反馈项,有效抑制系统模型不确定性。设计的控制器在参数不确定性、外部干扰、噪声存在的情况下,实现了四旋翼飞行器精确姿态跟踪。基于Lyapunov理论的稳定性分析验证了所设计控制器的收敛性。最后设计大量仿真和对比试验说明该姿态控制方法的有效性和鲁棒性。     

一类不稳定时滞对象的两自由度控制器设计

在化学工厂和工业工厂中会频繁出现一阶时滞不稳定系统难以控制的问题.针对该问题,文中提出两自由度控制器的改进方案.该改进方案的主体思路是,在保留原方案中设定值追踪控制器的控制器形式及算法不变的情况下,将其扰动控制器改用带超前滞后滤波器的PID控制器形式,并基于直接综合法对其进行参数整定,最后再根据鲁棒稳定性与抑制负载干扰...     

空间机器人全局逼近收敛控制

针对自由漂浮空间机器人系统,设计了一种全局逼近收敛控制器,解决了存在初始状态误差及外界干扰条件下的系统鲁棒性问题。首先,根据空间机器人系统的状态空间方程设计控制器,该控制器将控制输出特性与控制增益隔离开,对系统模型的不确定性及外界干扰具有强鲁棒性。另外,该控制方法避免了类似反演控制方法带来的复杂度高的问题。其次,从理论上证明了该控制器能够实现机器人系统对期望路径的跟踪。最后,针对单臂六自由度空间机器人系统,分别使用该控制器与鲁棒补偿控制器进行了仿真分析。仿真结果证实了该控制器的强鲁棒性。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first