利用信息融合方法的三维特征提取

本文提出了一种基于信息融合的物体三维特征的提取方法，该方法利用两幅互相配准的三维测距图像和灰度图像，来提取多面体的三维特征。首先，通过分析灰度图像中的灰度变化及测距图像中的测距值变化，分别求取各自图像中物体的特征点及特征边；然后，利用两配准图像之间的对应关系，求得所有特征点、面与多边形在三维测距图像中的三维表示；接着，通过分析三维测距图像中所测得的各候选平面上特定点与边处的曲率及法向，验证候选平面     

基于单片机的红外超声室内定位系统

介绍一个以单片机为主控制单元、红外和超声传感器为测距工具、采用三个参考点的较高精度室内定位系统。其中重点说明系统测距的原理与实现，详细论述了一种新的测距方法，并通过实际的测距实验说明此方法的可行性与优点。     

超声波测距自动定位系统的制作

超声测距自动定位系统具有结构简单,价格平宜,体积小,易于实时控制的优点,在测量精度和定位精度等方面能够达到工业应用的要求,应用日益广泛。由于单片机应用的迅速推广,自动化控制技术正以前所未有的速度发展,在各方面得到了广泛的应用。可移动智能机器人是世界各国开发的热点,也是工业自动化控制的重点研究课题,在各个领域正发挥着越来越重要的作用。本文所介绍的超声测距自动定位系统,能够通过超声测     

基于消息复用的TOF井下精确定位技术

针对目前超宽带TOF井下精确定位技术中对称双边双向测距(SDS-TWR)方法测距效率低、扩展性差,多次回应非对称双边双向测距(ADS-TWR-MA)方法测距效率及定位系统容量仍有提升空间的问题,提出了多标签多锚节点同时测距(ADS-TWR-MTMA)方法。该方法在多次回应非对称双边双向测距(ADS-TWR-MA)方法的基础上,进一步复用非对称双边双向测距过程中的测距消息,可以让多标签与多锚节点同时进行TOF测距,在保证测距精度的前提下大大提高了测距效率和定位系统容量。在机车接近探测系统和精确定位系统中的应用验证了ADS-TWR-MTMA方法在测距消息条数、测距耗时及系统容量上均优于SDS-TWR方法和ADS-TWR-MA方法。     

一种基于超声传感器的三维坐标测量方法

提出一种基于超声传感器的低成本三维测量方法.该方法采用一个超声波发射端和多个超声波接收端的组合,通过超声测距原理获得发射端到多个接收端的距离,从而计算超声波接收端的空间三维位置;在超声波三维测量方法的基础上,推导了基于最小二乘法的三维位置反演算法,搭建了基于FPGA的测量硬件系统并进行了实验研究.实验结果表明:坐标估计的绝对误差小于20 mm,重复性较好,测量精度有进一步提高的空间.     

基于红外超声光电编码器的室内移动小车定位系统

介绍一个二轮驱动移动小车的,定位系统,采用红外超声三边测距的绝对定位方法和光电编码器航迹推算的相对定位方法,比较准确的测量了小车的运行轨迹和方向,并解决了传统单纯依靠红外超声定位存在的盲区问题,实验说明此方法具有可行性。     

基于CC1101射频技术的室内超声定位系统

待定位物的三维坐标监测是室内定位的一个重要指标.文中采用射频技术作为测距时的内部同步设置,考虑到室内布局的复杂性,待定位点到各个已知参考节点的测距值的集中定位计算采用无线数据传输.通过应用射频芯片CC1101和ATmega48控制芯片组成的射频信号收发模块,实现了超声测距时的内部同步和无线数据传输,提高了定位的精度、增加系统灵活性,并适于特殊的场合.利用LabVIEW软件实现最终数据处理,使得设计直观、适应性更强.     

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。     

地面无线三维定位系统

本文介绍了一种地面无线三维定位系统,说明了其结构、功能、硬件、软件及其实现。采用信息广播机制的无线三维定位方法,实现独立网络支持下的具有分层结构的建筑区域中的移动人员的无线三维定位,可应用于大型、中型、小型等各类系统中。     

基于迭代的无线传感器网络三维定位算法

针对目前无线传感器网络三维空间定位存在精度不高、计算复杂、传输数据量大等问题,提出了一种基于测距的分布式算法———高精度迭代三维定位算法(ILAH-3D)。该方法将经典二维算法AHLos(Ad-Hoc Localization System)扩展到三维空间,通过采用加权最小二乘法和加入定位节点升级锚节点的验证条件来减少累计误差,提高节点定位精度,并根据三维空间中节点的各种位置关系,给出了约束协作算法的执行条件,然后结合升级的锚节点再进行新一轮的定位运算。该方法计算简单、通信量小,与已有三维定位算法相比,在测距存在一定误差的情况下,依然可以达到很好的精度。     

3-D positioning control by linear visual servoing

This article describes the performance of 3-D positioning control by linear visual servoing using binocular visual space in a human-like hand-eye system which has a similar kinetic structure to a human being. We approximate the nonlinear time-variant mapping from a binocular visual space to the joint space of the manipulator as a linear time-invariant mapping. We also investigate the effect of binocular visual space in linear mapping by comparing it with linear mapping using Cartesian space. Some experimental results are presented using the human-like hand-eye system to demonstrate the performance of 3-D positioning control. This work was presented, in part, at the Seventh International Symposium on Artificial Life and Robotics, Oita, Japan, January 16–18, 2002     

Artificial 3-D contactless measurement in orthognathic surgery with binocular stereo vision

Stereo vision systems are utilized since it provides contactless measurements of objects in 3-D (three-dimensional). Orthognathic surgery is a very sensitive operation that requires very high accuracy in measurements. The reduction of measurement error is an essential problem in orthognathic surgery. Moreover, quality inspection of the process during the course of operation aids the surgeon to avoid or minimize the mitigating circumstances. In this paper, artificial intelligence methods (neural network and neuro-fuzzy system) are used in order to increase the accuracy of positioning of jaws during the real-time practice. The comparison of artificial measurements with the real measurements shows that a statistically acceptable accuracy is achieved in 3-D positioning of teeth.     

A novel trajectory planning-based adaptive control method for 3-D overhead cranes

A three-dimensional (3-D) overhead crane is a complicated nonlinear underactuated mechanical system, for which high-speed positioning and anti-sway control are the kernel objective. Existing trajectory-based methods for 3-D overhead cranes focus on combining efficient and smooth trajectories with anti-sway tracking controllers without regard for payload motion; moreover, the exact value of plant parameters is required for accurate compensation during the control process. Motivated by these facts, we present a two-step design tracking strategy which consists of a trajectory planning stage and an adaptive tracking control design stage for 3-D overhead cranes. As shown by Lyapunov techniques and Barbalat's Lemma, the proposed controller guarantees asymptotic swing elimination and trolley positioning result in the presence of system uncertainties including unknown parameters and external disturbances. Simulation results also showed the applicability of the proposed method with good robustness against parameter uncertainties and external disturbances.     

三维传感网空间RSS与AOA混合测量的精确定位方法

由于位置坐标参数的增加,三维传感网空间的定位难度较二维平面有所增大.单一的依靠接收信号强度(RSS)确定节点位置坐标的方法将使定位的不确定性增加,定位误差也较大.新型的阵列与智能天线的出现为节点间的到达角度(AOA)测量提供了方便,为此本文提出了一种三维传感网空间RSS与AOA混合测量的精确定位方法.将采用混合测量建立的非线性优化模型转化为线性方程,分别提出了节点位置坐标估计的非约束线性最小二乘(ULLS)及约束线性最小二乘(CLLS)方法.仿真测试了所设计算法的有效性,分析了不同测量噪声对位置坐标估计误差的影响.仿真表明所设计的ULLS和CLLS方法的计算速度快,相比于ULLS方法,采用约束后的CLLS方法的定位误差更小.在较小测量噪声范围内,ULLS和CLLS估计方法具有较高的稳定性和定位精度.     

基于nanoLOC的嵌入式定位系统

研究了基于nanoLOC收发器的目标定位系统.嵌入式定位系统由三星S3C6410A微处理器,无线通信模块nanoPAN 5375以及液晶显示器等组成,以Linux2.6.38为内核的Linux操作系统为嵌入式软件平台.采用了双边双路对称测距算法(SDS-TWR),具有较高的定位精度.经过大量实验证明,该系统定位精度可以实现在1米以内,能满足室内外及对定位精度要求较高和恶劣环境下的定位,可用于手持式移动定位设备,具有很广的应用和推广价值.     

基于nanoLOC的嵌入式定位系统①

研究了基于nanoLOC收发器的目标定位系统．嵌入式定位系统由三星$3C6410A微处理器,无线通信模块nanoPAN5375以及液晶显示器等组成,以Linux2．6．38为内核的Linux操作系统为嵌入式软件平台．采用了双边双路对称测距算法（SDS·TWR）,具有较高的定位精度．经过大量实验证明,该系统定位精度可以实现在1米以内,能满足室内外及对定位精度要求较高和恶劣环境下的定位,可用于手持式移动定位设备,具有很广的应用和推广价值．     

一种用于锁定髓内钉的新型计算机辅助整形外科系统

介绍了一套用于整形外科的全自动机器人系统．该系统中的并联机器人取代了传统的复位工具,并提出了一种简单、准确的基于几何模型的对准方法,得到一条能够穿过髓内钉远端孔的三维路径,引导串联机器人锁定髓内钉．实验结果表明,该系统有足够的定位精度和稳定性,并可以大大减少手术所需时间．     

3-D relative positioning sensor for indoor flying robots

Swarms of indoor flying robots are promising for many applications, including searching tasks in collapsing buildings, or mobile surveillance and monitoring tasks in complex man-made structures. For tasks that employ several flying robots, spatial-coordination between robots is essential for achieving collective operation. However, there is a lack of on-board sensors capable of sensing the highly-dynamic 3-D trajectories required for spatial-coordination of small indoor flying robots. Existing sensing methods typically utilise complex SLAM based approaches, or absolute positioning obtained from off-board tracking sensors, which is not practical for real-world operation. This paper presents an adaptable, embedded infrared based 3-D relative positioning sensor that also operates as a proximity sensor, which is designed to enable inter-robot spatial-coordination and goal-directed flight. This practical approach is robust to varying indoor environmental illumination conditions and is computationally simple.     

Insight into spontaneous recurrent calcium waves in a 3-D cardiac cell based on analysis of a 1-D deterministic model

Calcium dynamics in a cardiac cell are described by a system of 3-D non-linear stochastic partial differential equations. To obtain solutions that have biophysical properties, it is necessary to explore the model parameter space. To decrease the complexity of the parameter search, we reduce the 3-D stochastic model to a 1-D deterministic model. The reduction of the problem from 3-D to 1-D is done through an asymptotic approximation after non-dimensionalization and based on rational biophysical assumptions of the 3-D domain; the stochastic to deterministic transformation is based on the regular property of the 3-D solution. The result of the model reduction proves very effective in reducing the time required to get qualitative as well as quantitative information about parameter regions in the 3-D stochastic model including calcium dynamics (sparks, wave propagation, and recovery) observed in cardiac cells.     

Three-dimensional hydrodynamic focusing in polydimethylsiloxane (PDMS) microchannels

This paper presents a generalization of the hydrodynamic focusing technique to three-dimensions. Three-dimensional (3-D) hydrodynamic focusing offers the advantages of precision positioning of molecules in both vertical and lateral dimensions and minimizing the interaction of the sample fluid with the surfaces of the channel walls. In an ideal approach, 3-D hydrodynamic focusing could be achieved by completely surrounding the sample flow by a cylindrical sheath flow that constrains the sample flow to the center of the channel in both the lateral and the vertical dimensions. We present here design and simulation, 3-D fabrication, and experimental results from a piecewise approximation to such a cylindrical flow. Two-dimensional (2-D) and 3-D hydrodynamic focusing chips were fabricated using micromolding methods with polydimethylsiloxane (PDMS). Three-dimensional hydrodynamic focusing chips were fabricated using the "membrane sandwich" method. Laser scanning confocal microscopy was used to study the hydrodynamic focusing experiments performed in the 2-D and 3-D chips with Rhodamine 6G solution as the sample fluid and water as the sheath fluid.