三维全身扫描仪的建模仿真

随着计算机全面进入3D时代，三维全身扫描系统对社会的价值越来越显著，获取人体表面的三维几何信息，是建立3D人体模型的先决条件。该文提出了一种基于结构光方法的三维全身扫描仪的系统仿真方案，使用3D Studio MAX软件仿真得到虚拟扫描头运动形成的带激光条纹的图像序列，最后用仿真数据进行三维重建。关键步骤包括用自适应阈值法提取激光带中心，深度图像的获取，以及多扫描头数据的融合等。实验取得了满意的效果，获得了人体的完整轮廓线，验证了系统仿真方案的合理性与高效性。     

双目结构光系统仿真建模和误差灵敏度分析

结构光系统目前在三维测量、逆向工程等领域应用日益广泛,然而关于结构光系统性能评测方法的研究成果仍然很少,仅有少数国际标准给出了3D扫描系统的性能评测方法.本文首先建立了双目结构光系统的仿真模型,其中包括了相机镜头畸变模型和针孔成像模型,实现投影仪投射数字正弦条纹的仿真和被扫描的靶球特征量仿真计算,采用的三维重建方法为光学三角法.然后基于仿真模型,对其基线距离相关的误差灵敏度进行了仿真,发现靶球中心位置和靶球球心距对基线距离误差具有较高的灵敏度,可以作为测试方法的输出.最后,如果只考虑基线距离误差,标准测试方法中的校准球棒的位置应在测量范围内的相对距离尽可能大,为标准性能评测方法提供了改进建议.     

基于结构光的三维测量及重建技术

本文介绍了利用结构光实现三维信息获取和重建的方法。该方法是利用结构光和ＣＣＤ摄像机构成的视觉系统对物体扫描,获取物体可视表面的相对三维坐标,建立不同视点下物体可视域的三维描述。通过对这些离散三维描述的拟合,获得寒带的物体三维描述,建立该物体的几何模型。该技术对拟实制造、仿真加工等应用领域具有重要的意义。     

新型移动机器人激光测距雷达的研究

研制了一种新型的基于激光结构光三维视觉技术的移动机器人模块化测距雷达样机,并提出了多平面靶标的转轴现场标定方案,为实现其对周围环境的扫描测量,首先标定线激光器与网络摄像头的相对位置,利用三角法测量激光交线到摄像头光心的距离。然后标定舵机转轴与摄像机的相对位置,并将旋转的激光交线坐标,统一到一个世界坐标系下,实现扫描测距。三维测量实验中,相对误差0.31%,系统测量误差小于4%。实验证明该样机测量精度高,成本低,具有广阔的应用前景。     

一种三维图形视景中激光测距的仿真方法

该文研究在三维图形视景中实现对任意目标的激光测距仿真。通过对生成三维图形视景变换矩阵的分析,提出了一种基于像素空间的激光测距仿真新方法。该方法充分利用了视景中三维数据的信息,不仅突破了传统方法只能对有限目标进行测距的限制,而且大大提高了测距的精度。基于像素空间的激光测距仿真方法,不仅适用于单车训练环境,而且也适用于红蓝对抗的战术环境。     

SMT封装电路板三维在线检测技术

为了检测回流焊接之后SMT( Surface Mount Technology)封装电路板是否存在缺陷,设计并搭建了基于线结构光传感器的SMT封装电路板三维在线检测系统,通过线结构光扫描测量,获取SMT封装电路板表面三维数据。采用双传感器测量技术,有效减少数据丢失;研究了双传感器统一标定技术,可同时实现两个传感器的参数标定和坐标系统一。提出了自适应光条中心提取算法,对反射或散射影响而形成的光条图像噪声具有很好的抑制效果,能够提取准确的光条中心。实验表明系统测量精度可达到0.02 mm。系统测量得到的三维数据,可以为在线检测SMT封装电路板缺陷提供可靠的三维信息。     

基于结构光的三维成像技术

就结构光三维成像的基本原理展开讨论,就投影图案的不同对结构光三维成像技术进行分类,对于每一类中选取其中具有代表性的几种方法进行描述,并给出三维成像技术的性能评价指标,对不同方法进行比较。介于定标精度对最终重建精度有着决定性的意义,我们对基于结构光三维成像系统的定标方法也作了简单介绍。     

基于光切法的三维脚型测量仪原理及系统设计

结合脚型三维轮廓测量仪的研究和设计，论述了如何将光切法用于脚型测量以及测量系统的组成，提出了采用多台CCDS摄像机从不同角度采样的空间匹配方法。介绍了三维轮廓测量中扫描控制系统的设计，从理论上论述了光切面轮廓图像的提取及处理，对测量仪中的误差进行了分析和讨论。实验结果表明系统具有良好的实用推广价值。     

基于非对称双相机结构光的三维扫描系统

提出一种基于非对称双相机结构光的三维扫描系统方案。采用结构光法测量深度,采用非对称布置的两台相机,在不降低系统精度的情况下减少遮挡的影响。分析了系统中两相机的成像关系,提出了系统定标和深度测量的算法。实验结果表明,该方法是有效的。     

基于CCD的三维形面测量系统研究

首先介绍了根据激光三角测距原理并采用片光照明、面阵CCD接收的三维形面检测原理及对映函数法原理,系统只用一个CCD测量头即可完成对物体进行360°的二维扫描,使测量系统结构简单、便于控制。其次分析了影响其测量准确度的几个主要因素,针对其各自的特点给出了相应的解决途径。实验证明系统设计方法是可行的。     

潜艇航行训练模拟器视景仿真中的三维场景显示

该文主要论述了在潜艇航行训练模拟器三维视景仿真中，把三维模型投影到屏幕坐标系当中的方法。该方法是利用Direct3D的几何管道，使模型中顶点依次经过世界变换、视变换、投影变换和屏蔽载减最后输出到光栅上。     

高精地图车道的三维可视化

为了在自动驾驶汽车开发中实现三维地图可视化呈现及在模拟器中模拟真实道路,提出一套数据还原技术。通过把原始数据采用的经纬海拔（WGS84）坐标系转换为地心地固（ECEF）坐标,利用三维建模软件（Blender）API实现在不对ESRI数据进行编译的情况下将数据自动化地生成多边形网格模型。同时为提高数据使用效率,进一步进行局部坐标分割,最大化模型使用便利性。生成的三维网格模型,分别为模拟器的物理模块和渲染模块所用。针对高视觉效果要求的场合,提出对地图数据点做插值优化的方法,实现了场景的逼真还原和良好的可视化效果,自动化流程因无人工参与从而可控制人为数据处理错误和提高效率。     

3D simulator for stability analysis of finite slope causing plane activity

This paper describes the development of a 3D simulator that enables a user to analyze the stability of a finite slope causing plane activity among a range of slopes comprised of a finite slope and infinite slope. Until now, there has been considerable theory and research into slope stability. Nevertheless, few systems can be confirmed directly by simulating the stability analysis of a slope, such as landslides. In other words, virtual experiments, such as the analysis of the slope, cannot be performed due to the absence of a system. For that reason, in this study, a 3D simulator was developed for stability analysis of a finite slope causing plane activity from the landslide phenomena that actually occurred or had very high probability. The Nvidia PhysX, which is utilized to develop computer games and simulators, was used to develop a 3D simulator with physical features. In addition, OpenGL was used to provide a three-dimensional visual effect from the simulator. In this paper, the values of each variable were determined to confirm whether landslides can occur easily when the factor of safety (F _s ) was within a certain range in the 3D simulator. The 3D simulator developed in this paper was found to be quite useful because it can verify visually whether landslides occur easily in different environments and conditions.     

Three-dimensional electromagnetic simulation of electronic circuits of general shape

A general purpose CAD tool, the IE3D electromagnetic simulator is presented in this article. The simulator is based on an integral equation, a method-of-moment formulation for a full-wave solution of three-dimensional (3D) arbitrarily shaped structures in microwave and millimeter-wave integrated circuits (MMIC), high temperature superconductor (HTS) circuits, microstrip antennas, RF printed circuit boards (PCB), and high speed digital circuit packaging. The primary solution of the simulator is the current distribution on a metallic structure in an environment of multilayered substrates on infinitely extended ground plane. The circuit parameters of the structure in either S-parameter form or RLC-SPICE equivalent circuit form is extracted from the solved current distribution. The simulator consists of an MS-Windows-based layout editor, a schematic editor, an electromagnetic simulator, and a post processor. The simulator can perform stand-alone electromagnetic simulation and optimization and mixed electromagnetic and nodal analysis. Simulation results for structures in various high frequency and high speed domains are presented and compared to measured results. © 1994 John Wiley & Sons, Inc.     

机场视景模型参数化建模方法研究

随着计算机虚拟现实和视景仿真技术的发展与完善,用于提高视景的逼真度和视觉效果的技术在飞行模拟机视景仿真中已得到广泛的应用。但是,基于Multigen Creator等3D建模软件构建机场模型的缺点日益凸显:人工收集机场数据、手工绘制机场拓扑图的建模方法耗时、费力、效率低、缺乏灵活性和可复用性。针对这些问题,结合机场路网结构的特点,将参数化的思想引入到机场路网三维建模过程中,提出了一种基于交通拓扑约束的机场路网参数化三维建模方法,设计并实现了基于该方法的用于视景的机场路网模型参数化建模系统。该系统已成功应用到机场模型建模工作中,建模速度较之传统方法有了显著的提高,而且制作出来的模型可以复用,系统在稳定性、可扩展性和可移植性方面表现出色,并具有很强的真实感和沉浸感。     

基于DirectX的虚拟驾驶模拟视景系统设计方法

根据虚拟汽车驾驶模拟视景系统的要求,提出了基于DirectX的视景系统的设计方法。使用3DMAX三维建模软件生成驾驶模拟的场景,采用了纹理映射技术、视景盒技术来优化场景,并应用DirectX提供的变换方法创建场景中的动画,实现了模拟真实雾的虚拟场景,生成了清晰、连续的虚拟驾驶模拟视景系统。     

Fuzzy logic based smart traffic light simulator design and hardware implementation

The objective of this study is to develop fuzzy logic based traffic junction light simulator system for design and smart traffic junction light controller purposes and also to observe its performance. Traffic junction simulator hardware is developed to overcome difficulties of working in a real environment and to easily test the performance of the controller. By using the traffic light simulator developed in this study, results of constant duration (conventional) traffic light controller and fuzzy logic based traffic light controller are compared where the vehicle inputs are supplied by the simulator. Statistical experimental results obtained from the implemented simulator show that the fuzzy logic traffic light controller dramatically reduced the waiting time at red lights since the controller adapts itself according to traffic density. It is obvious that the intelligent light controller is going to provide important advantages in terms of economics and environment.     

Fast optimization-based elasticity parameter estimation using reduced models

Elasticity parameters are central to physically-based animation and medical image analysis. We present an accelerated method to automatically estimate these parameters for a deformation simulator using an iterative optimization framework, given the desired (target) output surface/shape. During the optimization, the input model is deformed by the simulator, and the distance between the deformed surface and the target surface is minimized numerically. To accelerate the optimization process, we introduce a dimension reduction technique to allow a trade-off between the computational efficiency and desired accuracy. The reduced model is constructed using statistical training with a set of example deformations. To demonstrate this approach, we apply the computational framework to 2D animations of elastic bodies simulated with a linear finite element method. We also present a 3D elastography example, which is simulated with a reduced-dimension finite element model to improve the performance of the optimizer.     

航海模拟器视景中沿岸山脉实景纹理图象拍摄

航海模拟器是一种能部分模仿海上真实情况,专门为满足航海教育与培训、航海技术研究等目的而设计研制的装置,其核心技术之一是海上视景模拟。针对航海模拟器视景中岛屿与背景山脉纹理图象的拍摄与影像质量,给出理论依据、具体要求与实现方式,并分析了以实拍照片作为纹理源进行纹理映射的可行性。     

Depth-Fused 3D Imagery on an Immaterial Display

We present an immaterial display that uses a generalized form of depth-fused 3D (DFD) rendering to create unencumbered 3D visuals. To accomplish this result, we demonstrate a DFD display simulator that extends the established depth-fused 3D principle by using screens in arbitrary configurations and from arbitrary viewpoints. The feasibility of the generalized DFD effect is established with a user study using the simulator. Based on these results, we developed a prototype display using one or two immaterial screens to create an unencumbered 3D visual that users can penetrate, examining the potential for direct walk-through and reach-through manipulation of the 3D scene. We evaluate the prototype system in formative and summative user studies and report the tolerance thresholds discovered for both tracking and projector errors.