Research on Extraction of Bottom of Shoe Pattern Based on Binocular Stereo Vision

In order to quickly and efficiently get the information of the bottom of the shoe pattern and spraying trajectory,the paper proposes a method based on binocular stereo vision. After acquiring target image,edge detection based on the canny algorithm,the paper begins stereo matching based on area and characteristics of algorithm. To eliminate false matching points,the paper uses the principle of polar geometry in computer vision.For the purpose of gaining the 3D point cloud of spraying curve,the paper adopts the principle of binocular stereo vision 3D measurement,and then carries on cubic spline curve fitting. By HALCON image processing software programming,it proves the feasibility and effectiveness of the method.     

虚拟三维环境下阴影应用的研究

虚拟三维环境下的阴影对作品的艺术性有着极大的影响.通过论述了虚拟三维视觉艺术中阴影的相关原理及应用技术,并着重分析了其应用对于三维视觉艺术作品表达效果的重要意义,找出在虚拟三维环境下阴影应用和使用的方法.     

一种基于先验知识的3D位姿参数识别方法

计算机视觉中用单幅照片来识别三维物体的六个自由度是非常困难的，但是，在知道一些先验知识的情况下，可以对物体的六个自由度进行识别。本文提出一种基于先验知识的三维位举参数识别的方法，使用物体上不共线的三个特征点及目标点来确定物体的位置和姿态，给出了六个参数的解析表达式，在实时处理中可以得到好的效果。     

用于空空导弹弹道终端的ATR系统和算法

以工作在弹道终端的红外成像型空空导弹为对象,提出了一种基于前视红外图像的自动目标识别(ATR)系统,并建立了相应的ATR算法。此ATR既可以探测、识别、跟踪目标,还能够在弹道终端识别目标的易损(要害)部位,提取飞行剩余时间,自适应控制炸点。实测的弹道终端红外图像验证了这些ATR算法。     

3D Printed Functional and Biological Materials on Moving Freeform Surfaces

Conventional 3D printing technologies typically rely on open‐loop, calibrate‐then‐print operation procedures. An alternative approach is adaptive 3D printing, which is a closed‐loop method that combines real‐time feedback control and direct ink writing of functional materials in order to fabricate devices on moving freeform surfaces. Here, it is demonstrated that the changes of states in the 3D printing workspace in terms of the geometries and motions of target surfaces can be perceived by an integrated robotic system aided by computer vision. A hybrid fabrication procedure combining 3D printing of electrical connects with automatic pick‐and‐placing of surface‐mounted electronic components yields functional electronic devices on a free‐moving human hand. Using this same approach, cell‐laden hydrogels are also printed on live mice, creating a model for future studies of wound‐healing diseases. This adaptive 3D printing method may lead to new forms of smart manufacturing technologies for directly printed wearable devices on the body and for advanced medical treatments.     

Von Karman导弹弹头的等离子体隐身研究

文章介绍了时域有限差分法(FDTD)算法的基本原理和等离子体的Debye模型,分析了等离子体隐身的基本原理.以Von Karman导弹弹头为隐身目标,用3DSMAX建立弹头和等离子体层的三维模型,然后导入到基于FDTD算法的电磁仿真软件XFDTD中,计算了不同等离子体频率和碰撞频率下弹头的后向散射,给出了相应的频率-雷达截面积曲线.最后对仿真结果进行了分析,并总结了等离子体隐身的规律和特点.     

双目立体视觉的远距离运动物体运行姿态研究

提出了一种采用双目立体视觉测量技术来获得炮弹运行姿态的新方法.首先利用加权平均的方法求炮弹的质心,然后利用炮弹表面点到弹轴的距离相等的原理,用最小二乘拟合法推导出弹轴方程,得到弹轴矢量,最后通过建立弹轴矢量与姿态角之间的数学关系得到炮弹运行时的姿态角.仿真实验结果表明,该测量方法具有较高的精度,能满足远距离运动物体运动参数的测量要求.     

立体视觉曲面重建与系统误差分析

采用立体视觉空间曲面重建技术对三维曲面表面成像进行边缘提取、图像匹配、匹配点空间位置计算等步骤,得到三维曲面表面点的空间位置,利用空间点信息对三维曲面形状进行重建,恢复曲面三维形状;并讨论了立体视觉系统的摄像机分辨率、测量范围和摄像机间距等参数之间的关系.利用该方法对堆积物表面形状及体积进行测量实验结果表明,该方法能准确、快速、方便地给出三维曲面的形状.     

Design and development of a low-cost laser range sensor

Active 3D vision is concerned with extracting 3D information from the visible surfaces of the scene. With the use of recent technological advances made in electronics, photonics and computer vision, it is now possible to develop a reliable, high-resolution and accurate 3D active range sensor. In this paper, first we present the development of Laser range sensor using only consumer-grade technologies to ensure affordable hardware cost and high angular resolution. In the designed Laser range sensor, a diode Laser projects the Laser line on the surface through a cylindrical lens while the camera captures the Laser line profile. Next, a new calibration technique of the range sensor is presented to acquire the range information based on relative pose between the Laser and the camera by taking single view of the scene. Experiments are carried out on real scene and efficient 3D reconstructed model of the objects has been obtained.     

标定十字结构光传感器的新方法

建立了基于十字结构光的视觉传感器的数学模型,提出了一种基于自由移动平面靶标的十字结构光传感器参数的简易标定方法。在自由移动的平面靶标上建立局部世界坐标系,将通过交比不变方法获得的两个光平面上特征点的局部世界坐标,变换到摄像机坐标系,从而获得已知三维的标定特征点。利用构建的分别位于两个光平面上标定特征点,可以实现工作状态的十字结构光传感器参数的优化估计。该标定方法降低了标定设备的成本,简化了标定过程,为十字结构光传感器的工程化应用奠定了基础。通过对圆的直径和中心坐标的测量实验,结果表明,该方法切实可行。     

汽车车身模型立体视觉测量系统

针对汽车车身开发的要求,采用计算机立体视觉技术,建立一套适用于车身模型表面三维数字化的非接触式测量系统。     

Research and realization of an auto-calibration technique based on stereovision

The purpose of this research is to analyse the present-day state of calibration techniques and to realize an auto-calibration technique based on a projected grating 3D measuring system. An auto-calibration technique, called multiple target tracking for detecting outlines based on random placing and regular numbers, was proposed. The practical algorithm was also presented at the same time. According to this arithmetic, the relevant experimental result was gained. Furthermore, the precision of the calculation result was analyzed. The results showed that the operation was simplified, the orientation precision of image outline edges was ensured and calibration precision was kept within 0.02–0.05 mm by using the arithmetic in this work. The research verified the feasibility of auto-calibration, providing arithmetic that is extremely useful for the industrial application of computer vision technologies. The paper deals with experimental work on innovative techniques for which the data have not been seen in the literature. In particular, an original auto-calibration technique, which is named as multiple target tracking for detecting outlines based on random placing and regular numbers, was provided.     

Demonstration of improved automatic target-recognition performance by moment analysis of correlation peaks

We report the results of experimental tests of an optical-correlator-based automatic target recognition (ATR) system that uses the correlation-peak moment analysis technique of Caprari [Appl. Opt. 38, 1317 (1999)] to assist in discrimination between target and clutter peaks. The ATR system and its operation are briefly described with particular attention devoted to a practical scheme for enhancing the basic ATR system with correlation-peak moment detectors. We investigate the variation of detection and false-alarm rates of moment detectors with moment threshold values. For fixed moment thresholds, we present receiver operating characteristics of both basic and enhanced systems as the conventionally used correlation-peak energy threshold is varied. Results demonstrate that correlation-peak moment analysis materially improves ATR system target-detection performance.     

一种高效的实时视觉姿态测量

由光学传感器和计算机视觉理论来确定目标物体的姿态参数具有重要的实用价值和理论意义.本文以提高当前物体姿态求解方法的实时性和准确性为目的,提出一种高效的基于特征点的姿态求解方法,该方法首先采用P3P算法求解目标物体的近似姿态,然后将该近似姿态作为初始值嵌入正交迭代(OI)优化算法求取目标姿态的最优值,该方法可以适用于任意...     

从导弹战斗部用钛合金的研究看材料的开发

从高速冲击动力学的角度出发，分析了影响导弹战斗部同目标撞击时的因素，讨论了层状结构的钛合金用作高速半穿甲战斗部的可能性，进而表述了服役效能在材料开发中的核心地位。     

Three-dimensional vision from a multisensing mechanism

An approach for sensing a three-dimensional (3D) object surface with an arbitrary geometric shape is presented. Combining two different 3D sensing mechanisms, point-array encoding based on affine transformation and fringe encoding based on phase mapping, we construct a mathematic model for 3D vision in which the point-array encoding is initially applied to determine the fringe orders to create a control-vertex mesh with absolute coordinate values in 3D space. Then phase evaluation and phase unwrapping for fringe decoding is performed under the guidance of control-vertex mesh, leading to an absolute phase map and the corresponding range image of the test object. The computer simulations and experimental results are presented to demonstrate the theoretical prediction.     

一种基于双信息源的人手空间跟踪方法

对人手的空间运动进行了分析和建模，提出了一种利用双信息源进行人手空间定位的新方法。利用视觉输入提取手的平面位置信息。借助安装于肘部的弯曲传感器获取手臂的弯曲角度。根据所建模型由二者通过模糊计算确定手的深度信息。通过实验，证实了该方法的有效性。     

3D Jet Writing: Functional Microtissues Based on Tessellated Scaffold Architectures

The advent of adaptive manufacturing techniques supports the vision of cell‐instructive materials that mimic biological tissues. 3D jet writing, a modified electrospinning process reported herein, yields 3D structures with unprecedented precision and resolution offering customizable pore geometries and scalability to over tens of centimeters. These scaffolds support the 3D expansion and differentiation of human mesenchymal stem cells in vitro. Implantation of these constructs leads to the healing of critical bone defects in vivo without exogenous growth factors. When applied as a metastatic target site in mice, circulating cancer cells home in to the osteogenic environment simulated on 3D jet writing scaffolds, despite implantation in an anatomically abnormal site. Through 3D jet writing, the formation of tessellated microtissues is demonstrated, which serve as a versatile 3D cell culture platform in a range of biomedical applications including regenerative medicine, cancer biology, and stem cell biotechnology.     

复杂背景下导弹目标的分光检测

针对电视制导系统从各种复杂自然背景和野战环境的图像中提取导弹目标信号的要求,从导弹目标和背景的光谱特性出发,提出了导弹目标的分光检测原理与方法,设计了双CCD分光检测光学系统,使含有导弹目标的图像进入主CCD,背景图像进入次CDD,最终由背景减法电路实现主次CCD图像相减,得到导弹目标图像.实验结果证明,该方法能可靠地从背景中检测出导弹目标.     

由序列图像进行三维测量的新方法

目前的三维测量方法都需要专门的测量设备且存在着种种限制,为此提出了一种基于图像序列进行三维测量的新方法。将由数码相机围绕被测物体拍摄的多幅图像导入计算机,利用图像处理知识得到特征的二维信息;采用计算机视觉方法,对特征从射影空间到欧式空间分层逐步重建即可完成三维测量。设计一套特征标志组合,作为辅助测量工具避免了特征匹配难题。确立了一套图像分割与识别策略获得特征标志二维信息,识别率可达到95%以上。采用基于模约束的摄像机分层自标定方法得到特征在欧式空间下的三维信息,并通过多种优化方法减少误差的影响。该方法在硬件上实现简单,对测量条件要求不高。实际试验表明,相对误差可达到1.48%,重投影误差为0.3864像素。