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71.
Dynamics of the explosive growth of a vapor bubble in microgravity is investigated by direct numerical simulation. A front tracking/finite difference technique is used to solve for the velocity and the temperature field in both phases and to account for inertia, viscosity, and surface deformation. The method is validated by comparison of the numerical results with the available analytical formulations such as the evaporation of a one-dimensional liquid/vapor interface, frequency of oscillations of capillary waves, and other numerical results. Evolution of a three-dimensional vapor nucleus during explosive boiling is followed and a fine scale structure similar to experimental results is observed. Two-dimensional simulations yield a similar qualitative instability growth.  相似文献   
72.
卡尔曼滤波器在光电经纬仪中的应用   总被引:6,自引:2,他引:4  
为了解决光电经纬仪电视跟踪系统脱靶量滞后对控制系统跟踪精度及稳定性的影响,将预测滤波技术应用到光电跟踪系统中,提出了极坐标下卡尔曼滤波算法,目标模型采用等速运动并附有时间相关的随机加速度,增加了延时补偿。仿真结果表明,跟踪误差减小,当跟踪目标从视场消失时,控制系统按照预测的目标信息跟踪。  相似文献   
73.
描述了仿人智能用于光电跟踪控制系统的设计思想和方法。给出了利用这一设计方法在一大型光电跟踪镜上的控制结果。  相似文献   
74.
一种弧焊机器人实时激光扫描视觉系统   总被引:2,自引:0,他引:2  
研制了一种小型高精度弧焊机器人实时激光扫描视觉系统,对其各项性能进行了测试,并进行了抗电弧光干扰试验,结果表明,此系统精度高,抗干扰能力强,检测范围宽,能广泛地应秀于机器人和自动化焊接中。  相似文献   
75.
在对高速运动目标进行高精度的跟踪测量时 ,常采用高帧频电视跟踪系统。针对高帧频电视象元分辨率低、处理时间短、信噪比低的特点 ,对其定位跟踪算法进行了研究。  相似文献   
76.
Previously, researchers raised the accuracy for a robot’s hand to track a specified path in Cartesian space mainly through increasing the number of knots on the path and the number of the path’s segments, which results in the heavier online computational burden for the robot controller. Aiming at overcoming this drawback, the authors propose a new kind of real-time accurate hand path tracking and joint trajectory planning method. Through selecting some extra knots on the specified hand path by a certain rule and introducing a sinusoidal function to the joint displacement equation of each segment, this method can greatly raise the path tracking accuracy of robot’s hand and does not change the number of the path’s segments. It also does not increase markedly the computational burden of robot controller. The result of simulation indicates that this method is very effective, and has important value in increasing the application of industrial robots. Foundation item: Foundation of the Robotics Laboratory, Chinese Academy of Sciences (No. RL200002) Biography of the first author: TAN Guan-zheng, Dr., professor, born in Oct. 1962, majoring in artificial intelligence, robotics and automation.  相似文献   
77.
The techniques for image analysis and classification generally consider the image sample labels fixed and without uncertainties. The rank regression problem studied in this paper is based on the training samples with uncertain labels, which often is the case for the manual estimated image labels. A core ranking model is designed first as the bilinear fusing of multiple candidate kernels. Then, the parameters for feature selection and kernel selection are learned simultaneously by maximum a posteriori for given samples and uncertain labels. The provable convergency Expectation Maximization (EM) method is used for inferring these parameters in an iterative manner. The effectiveness of the proposed algorithm is finally validated by the extensive experiments on age ranking task and human tracking task. The popular FG-NET and the large scale Yamaha aging database are used for the age estimation experiments, and our algorithm outperforms those state-of-the-art algorithms ever reported by other interrelated literatures significantly. The experiment result of human tracking task also validates its advantage over conventional linear regression algorithm. A short version of this paper appeared in ICME07.  相似文献   
78.
Research presented in this paper deals with the systematic examination, development, and evaluation of a novel multimodal registration approach that can perform accurately and robustly for relatively close range surveillance applications. An analysis of multimodal image registration gives insight into the limitations of assumptions made in current approaches and motivates the methodology of the developed algorithm. Using calibrated stereo imagery, we employ maximization of mutual information in sliding correspondence windows that inform a disparity voting algorithm to demonstrate successful registration of objects in color and thermal imagery. Extensive evaluation of scenes with multiple objects at different depths and levels of occlusion shows high rates of successful registration. Ground truth experiments demonstrate the utility of the disparity voting techniques for multimodal registration by yielding qualitative and quantitative results that outperform approaches that do not consider occlusions. A basic framework for multimodal stereo tracking is investigated and promising experimental studies show the viability of using registration disparity estimates as a tracking feature.  相似文献   
79.
探讨了激光雷达的特性、工作原理以及相对于微波雷达的优势,并提出了现在乃至将来激光雷达作为现行装甲车辆传感器的重要补充手段,在高精度跟踪测量、高分辨率目标识别和三维成像等方面的应用前景,并论述了激光雷达存在的缺点和改进方法。  相似文献   
80.
一种识别薄板对接接头的视觉方法   总被引:1,自引:0,他引:1  
对薄板紧密对接接头的识别问题进行了深入的分析,提出了由照明、自适应局部特征提取、全局特征识别和验证融合在一起的视觉识别方法。它克服了电弧光的干扰,识别结果可靠,可以有效地解决薄板紧密对接接头识别这一难题。  相似文献   
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