激光跟踪虚拟坐标测量系统与自标定方法的实验研究

激光跟踪虚拟坐标测量系统满足了工业领域大型工件和空间形位测量所提出的要求。这些要求包括 :高精度、无导轨测量、动态实时跟踪测量、全姿态测量等。在实验室建立了基于角度 距离法的激光跟踪测量系统和基于纯距离法的多站跟踪测量系统 ,分别在三坐标测量机、光学平台光栅位移系统下进行了实际跟踪测量和精度比对实验。并运用虚拟坐标自标定算法在虚拟坐标系下确定了初始点位置、目标点坐标及各点间距离。最后 ,对两种方法的特点进行了分析比较     

电视跟踪在光电火控系统中的应用及发展趋势

电视跟踪在各种武器系统中得到越来越广泛应用。根据电视跟踪的工作原理和特点,论述电视跟踪在光电火控系统中的应用。分析国内外技术水平,并对其发展趋势进行了展望。     

Numerical simulation of shock wave interaction with a water column

The paper describes a scheme which is based on the CIP scheme and modified to properly describe a gas/liquid interface without smearing the density jump across the interface. This was achieved by calculating the density separately for each phase. The density at each grid point was determined by using a density function in a similar fashion as CIP. As a result a sharp density gradient was obtainable throughout the flow field and the scheme could handle properly gas/liquid interfaces having a large density ratio. Shock wave interaction with a cylindrical water column was simulated. The numerical results were compared with appropriate interferograms. Good agreement was found between the two. The results obtained for the cylindrical water column were compared with a similar solid cylinder case. The comparison reveled that even 40 s after shock impingement some differences were found between a liquid column and the solid cylinder. Received 11 July 2000 / Accepted 28 March 2001     

Implementation of opto-digital stereo object tracking system

In this paper, a new opto-digital stereo object tracking system using the variable window mask and the optical binary phase extraction joint transform correlator (BPEJTC) is proposed. At the first step, with the distance information from the stereo camera to the tracking object easily acquired by the structural elements of a stereo vision system, the area of the tracking object can be digitally extracted by using the variable window mask. And, at the second step, by carrying out the optical BPEJTC between this reference image obtained from the variable window mask and the stereo input image, the coordinates of the tracking object's location can be acquired, and then with these values, the convergence angle and the pan/tilt of the stereo tracking camera can be finally controlled. From some experimental results, the proposed system is found to be able to effectively extract the area of the target object from the input image having the background noises by using the variable window mask. And, with the location values of the tracking object obtained by using the optical BPEJTC, the convergence angle and the pan/tilt of the stereo cameras can be controlled. Finally, a feasibility of real-time implementation of the adaptive stereo object tracking system using the proposed algorithm is also suggested.     

Mode of Myosin Transportation in Living Cells Studied by Single Particle Tracking

The transport of internalized ?1A-adrenergic receptor (?1A-AR) by myosin protein in live cells was studied. The technique of single particle tracking by °uorescence imaging with high temporal and spatial resolution was used. The endosomes of ?1A-AR were transported along actin ˉlaments in a step-by-step mode. The average step-size in di?erent time resolutions is consistent with the step-size of myosin assay in vitro. With the simulation of the stepwise traces in di?erent time resolutions, we found that the kinetic process of each step is in coherence with the single myosin assay in vitro.     

椭圆偏振光谱方法对电化学的研究及应用

椭圆偏振光在固体表面入射和反射后,光学参量△,Ψ及其所表征的偏振状态,将因固体表面膜的厚度、性质不同而发生相应的变化．测定△,Ψ及其变化规律、可为固体材料、表面膜厚度、表面或界面上发生的有关物理或化学变化等直接或间接地提供信息,其灵敏度可反映表面膜层０．１～０．０１ｎｍ厚度的变化．因此,椭圆偏振光谱（下称椭圆法）在固体物理、表面化学、金属表面腐蚀、生物大分子表面等研究领域具有重要价值［１］．该法能检测的表面膜厚相当于电极上的单分子层的尺寸,特别适用于从分子水平上研究电化学体系,是最灵敏的光谱电化…     

一种基于人眼视觉系统特性的粒子滤波跟踪方法

通过模仿人眼跟踪运动目标的特点,对粒子滤波框架进行改造,提出了一种基于人眼视觉系统特性的粒子滤波跟踪算法。该算法采用多特征融合,将颜色特征与运动面积特征相结合,对运动区域比较敏感;在状态更新阶段,对跟踪粒子进行进一步筛选,自适应地选择性能良好的粒子进行结果判决,保障了跟踪结果的准确性。实验表明,该方法不仅可行,而且具有良好的跟踪效果。     

多特征融合匹配的多目标跟踪

针对复杂背景的视频图像多目标跟踪遮挡问题,提出了一种多特征融合匹配的多目标跟踪方法。基于自适应高斯混合背景模型重构和更新背景策略,实现当前帧背景减除和多目标检测;采用目标的颜色特征、质心位置、运动速度等特征进行融合匹配跟踪;最后,通过区域辅助判定策略将场景下的目标状态分为目标进入场景、目标退出场景、目标暂消、目标重现、目标融合和分裂5种状态,用质心预测方法和遮挡因子辅助匹配来提高匹配正确率。仿真实验结果表明：采用该方法跟踪同一目标和不同目标的相似度平均值分别为0.949 71和0.505 73,优于单一颜色特征信息匹配;目标遮挡结束后重新匹配相似度为0.972 83,实现了复杂背景下具有表面相似性的多目标实时跟踪。     

平面波经颅超声成像相位校正及散斑跟踪

准确的脑血流成像对脑功能监测和脑疾病的快速诊断具有重要意义,然而颅骨对超声传播的影响会导致成像质量下降、速度或位移估计不准确等问题.论文采用平面波相干复合结合散斑跟踪方法进行颅内散射目标成像和速度估计,以实现脑血流速度矢量检测;针对颅骨存在导致的超声相位畸变,利用数值仿真和体模实验研究了其对成像及散斑跟踪效果的影响,并...     

Hénon混沌系统的追踪控制与同步

基于离散线性系统的稳定性理论,实现了Hénon混沌系统对参考信号的追踪控制.讨论了系统的同步问题,给出了“异结构混沌同步”的新概念.数值仿真表明了本文方法的有效性 关键词： Hénon混沌系统 追踪控制 混沌同步