Calibration of an smt robot assembly cell

A new calibration method for an assembly robot cell is described. The proposed method is a combination of a model-free, numerical, relative robot calibration procedure and a procedure for the robot periphery calibration. Two important simplifications based on the study of an assembly process are introduced into the calibration strategy. A robot is calibrated in a task (Cartesian) space. The robot workspace and the number of calibrated degrees of freedom (dof) in the task space are reduced in accordance with the difficulty measure of the task. An automatic measurement system for measuring the relative robot accuracy was developed. An original principle of transforming the robot endpoint approach distance into the one-dimensional position displacement error is introduced. The accuracy errors of each particular calibrated dof in the task space is measured separately. The error tables are used in a direct robot calibration procedure that is based on the linear interpolation of the discrete position-error functions. An iterative inverse calibration algorithm used in a particular robot cell is described. An efficient sensor-based system for an additional simultaneous robot periphery calibration is presented. The implementation of the proposed calibration methodology in the pick-and-place robot cell for Surface Mount Technology (SMT) is presented. © 1994 John Wiley & Sons, Inc.     

宽频带梯度水听器校准系统中的数据采集与处理

研制了适用于宽频带梯度水听器校准系统的数据采集板及预处理差分放大器，并且在这些硬件基础上研究设计了专门的软件程序，实现实量系统控制及流程控制，并且可以在多信息界面提示下进行相应的手动操作。本系统具有数据采集、数据处理、图形控制以及图形和数据表格方式输出结果等功能。     

一种雷达和摄像机的空间标定方法

多传感器融合技术已经广泛应用在智能汽车环境感知领域中;雷达和摄像机的空间标定是伴随信息实时融合的道路检测技术的基础;结合智能汽车的实际应用,提出了针对激光雷达和摄像机的空间标定方法;通过特制的标定板来获得雷达数据和图像数据,选取激光雷达坐标系作为世界坐标系,通过参数拟合的方法来求取图像坐标系与雷达坐标系的变换关系,进而实现两种传感器的空间配准;该方法只需要标定板就能够完成激光雷达和摄像机的空间标定,标定精度高,实现了多个传感器世界坐标系的统一,避免了后续处理中数据解释的二义性;实验结果表明这种方法简单准确,满足系统要求。     

星载SAR传感器外场定标实验研究—以TerraSAR-X卫星为例

传感器的定标精度是衡量SAR卫星系统性能和数据质量的重要标志。以TerraSAR\|X卫星为例,系统设计了外场定标实验流程,围绕高精度获取参考目标外场实际几何坐标和散射截面积的目标,对角反射器的设计与制作、布设方案、状态参数计算和坐标精密测量等问题进行了研究。基于同步获取的SAR数据和外业数据,进行了TerraSAR\|X几何和辐射定标参数的精度验证。验证结果证明了实验总体设计和关键问题解决的有效性,对于其他星载SAR定标工作具有借鉴意义。
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基于PXI总线的自动检定系统

大型自动测试系统测试信号和测试路数多,检定过程较为费时,且需要专门的高精度仪器,为了实现复杂测试系统的系统级自动化检定,分析了现有自动测试系统的控制方式、检定要求,提出了基于PXI总线的系统级自动检定系统方案;利用PXI高精度仪器式模件,综合利用信号高压放大、调理和统计分析技术、虚拟仪器技术等,对电压、频率、时串和电阻等电量信号进行检定,研制的检定系统可对测试系统进行快速、自动检定.     

Calibration method for depolarization lidar measurements

A new method has been developed for calibration of the depolarization measurement of an atmospheric lidar. The technique requires a simple polarizer, and can be performed without interfering with the measurement set-up. The theoretical background of the procedure will be given and results of this calibration procedure on the tropospheric stratospheric aerosol lidar in McMurdo will be presented.     

Calibration of multi-beam laser tracking systems

Laser tracking systems (LTSs) employ tracking laser interferometers for coordinate measuring of precision machine tools and robots. Such coordinate measuring machines, if properly calibrated, are potentially fast, very accurate and can cover a large workspace. LTS devices must be self-calibrated, using redundancy or constraint surfaces.A methodology for self-calibration of a multi-beam LTS utilizing planar constraints is formulated and demonstrated. A kinematic model of a multi-beam LTS is derived. Model error analysis demonstrates that the use of angular measurement of the gimbal joint positions, relatively inaccurate as these are, does improve the overall system calibration accuracy. Self-calibration model parameters observability of the multi-beam LTS is studied. The results reveal the applicability of planar constraints to system self-calibration. Simulation and experimentation results obtained on a prototype system are reported demonstrating the applicability of the calibration strategies.     

摄像机标定系统的设计与实现

系统采用的是直接标定摄像机内部参数的算法，算法借助于标定参照物直接计算摄像机的内参数。整个系统是在VC++环境下设计并实现的，并借助了IPL和OpenCV的帮助，只要输入标定物的图像，系统就可以迅速而又准确地输出摄像机内参数的结果。通过3D重构实验证明了该系统的有效性。相对于MATLAB实现方式，该系统使用更加方便、快捷。     

Calibration of a measuring robot: Experimental results on a 5 DOF structure

An original method for the static calibration of robots using the pose matching approach is presented. Three algorithms for the identification of the structural parameters are investigated. The procedure includes a methodology to automatically remove the unnecessary parameters for the robot under analysis. After a theoretical introduction, the methodology is practically applied to an actual 5 DOF measuring robot used in a shoe manufactory industry. The accuracy of the robot is increased up to its repeatability. © 2001 John Wiley & Sons, Inc.     

Fully Vision-based Calibration of a Hand-Eye Robot

This article is concerned with calibrating an anthropomorphic two-armed robot equipped with a stereo-camera vision system, that is estimating the different geometric relationships involved in the model of the robot. The calibration procedure that is presented is fully vision-based: the relationships between each camera and the neck and between each arm and the neck are determined using visual measurements. The online calculation of all the relationships involved in the model of the robot is obtained with satisfactory precision and, above all, without expensive calibration mechanisms. For this purpose, two new main algorithms have been developed. The first one implements a non-linear optimization method using quaternions for camera calibration from 2D to 3D point or line correspondences. The second one implements a real-time camera pose estimation method based on the iterative use of a paraperspective camera model.     

简述极化SAR定标处理技术研究进展

极化定标是极化SAR数据用于图像解译和定量参数反演的关键步骤。综述了国内外极化SAR定标技术及应用研究的主要成果,着重介绍极化SAR定标技术发展以来取得的多种关键算法进展,系统梳理包括点目标定标算法、分布目标定标算法、法拉第旋转校正算法等技术原理介绍、参数定义估计及技术脉略发展分析,并讨论各技术方法在机载及星载SAR系统定标领域取得的应用发展现状,同时逐步分解该技术领域目前面临的技术难点及算法发展。最后探讨分析极化SAR定标技术发展中的未来需求难点和继续需要解决的问题,为研究人员进一步推动极化SAR定标技术发展提供参考。     

电子仪器自动校准与检测软件系统设计与实现

主要阐述对电子测量仪器进行自动检定与校准软件平台的设计与实现。系统采用VisualC＋＋软件设计技术模拟人工检定／校准过程;通过使用VISAI／O接口函数库实现了软件兼容常见仪器接口（GPIB、RS232、TCPIP、USB）的设计目标;使用数据库技术及提供开放式的检定／校准流程、测量功能（检定／校准方法）设计工具实现了软件和具体仪器资源无关、特别是与检定规程或校准方法无关的设计目标。     

Kinematic Calibration and Pose Measurement of a Medical Parallel Manipulator by Optical Position Sensors

In the applications of parallel manipulators, kinematic calibration is required to eliminate the errors resulting from the manufacturing and assembly of both base and tools. In this paper, a calibration method of base and tool transformation is developed by virtue of optical position sensors. An error model for calibration is constructed using differential geometry method. The pose error is obtained based on pose measurement results of OPTOTRAK 3020, a commercial 3D position measurement system. An iterative least squares procedure is used to identify the error parameters in the base and tool transformations. Simulation and experiment results are presented to demonstrate the effectiveness of the method for transformation matrices calibration. © 2003 Wiley Periodicals, Inc.     

A Calibration Procedure of Dynamic CGE Models for Non-Steady State Situations Using GEMPACK

This paper is concerned with the development of a calibration procedure for dynamic CGE models for non-steady state situations. While the literature on calibration of dynamic models mainly concentrates on the process of calibration in the context of a steady state, this essay centers upon the calibration procedure for the case that the model's state variables are not initially at their steady state values. Though this is the more realistic interpretation of a base year's data set it raises a number of additional difficulties including intertemporal feedback and the requirement that the basic data are consistent with the intertemporal equations of the model. These difficulties are discussed and a procedure is presented which can cope with them. Finally, the procedure is applied to an overlapping generations growth model with foresight and the steps involved in calibration are illustrated in detail.     

IMU标定数学建模及误差分析

惯性测量单元（IMU）标定路径设计和数据处理方法取决于IMU标定数学模型,安装误差是决定IMU标定模型的重要因素。针对工程中加速度计和陀螺相对载体安装方式的不同,提出一种通过坐标系转换矩阵建立IMU标定数学模型的方法,推导IMU标定模型误差与载体角速度和加速度之间的关系,分析IMU标定模型误差对捷联惯性导航系统导航参数的影响,并利用转台提供的位置信息设计IMU标定路径和数据处理方法。仿真和转台实验结果表明：IMU标定数学模型误差引起捷联惯性导航系统速度误差、位置误差和姿态误差;安装误差的表现形式决定了IMU标定模型误差对系统导航精度的影响。     

备份航姿系统的磁传感器在线校准方法

磁航向角是备份航姿系统的重要输出参数,为提高测量性能,需对磁传感器进行误差标定。对于机载应用的磁传感器,地面标定方法需要耗费大量的时间且操作不便,在地表标定结果的适用性随距离标定的时间和使用空间位置的变化而降低。基于备份航姿系统的实际工作特点,提出一种在备份状态下利用飞机主惯导的姿态角信息对磁传感器误差进行在线校准的方案,设计了误差校准数据存储的数据结构,提出了校准数据对航向空间覆盖的充分性评价策略,最后利用无磁转台模拟环境,验证了某备份航姿系统的磁传感器在线校准方案的可行性和有效性。     

Calibration of microsimulation traffic model using neural network approach

This paper presents the results of research on the applicability of neural networks in the process of computer calibration of a microsimulation traffic model. VISSIM microsimulation model is used for calibration done at the example of roundabouts in an urban area. The calibration method is based on the prediction of a neural network for one traffic indicator, i.e. for the traveling time between measuring points. Besides the traveling time, the calibration process further/also involves a comparison between the modeled and measured queue parameters at the entrance to the intersection. The process of validation includes an analysis of traveling time and queue parameters on new sets of data gathered both at the modeled and at a new roundabout. A comparison of the traffic indicators measured in the field and those simulated with the calibrated and uncalibrated microsimulation traffic model provides an insight into the performance of the calibration procedure.     

双PTZ摄像机系统的标定

在视频监控领域,PTZ(Pan/Tilt/Zoom)摄像机因为其具有可变视角和可变焦能力,已经越来越多的被采用,而且用两个PTZ摄像机组成一个视觉系统具有可以同时获取全景图像、近景高分辨率图像以及场景深度信息等优势,虽然目前关于双PTZ视觉系统的研究还比较少,但其应用潜力很大。对双PTZ摄像机系统进行标定的目的之一是辅助两个镜头之间的配准,进而方便立体匹配等。两个摄像机之间公共坐标系的选择是标定问题种的一个关键。针对这一问题提出了一种球面校正公共坐标系,并研究了其标定问题。众所周知,传统的多目镜头标定主要针对静止镜头,而且一般是通过事先估计摄像机的架设位置或者利用标定物来计算摄像机之间的关系,但此类标定方法无法直接解决上述问题。为了更好地进行标定,在此提出了一种利用多组基础矩阵的方法进行自动估计的标定方法,该方法不需要标定物,而只与镜头架设方式有关,且不受摄像机PTZ参数改变影响。实验结果表明,该方法具有方便和实用性。     

模糊化神经网络在摄像机标定中的应用

摄像机标定是精确的视觉系统的前提。该文提出了基于双目视觉的一种新型模糊化神经网络摄像机标定法。神经网络已经成功的运用于无参摄像机标定技术当中。由于镜头的畸变主要由径向畸变引起,且图像中点总的径向畸变正比于该点到图像中心距离的平方,所以通过对神经网络的输入层进行径向模糊化,可以进一步精确标定结果。通过与普通神经网络摄像机标定法、分割区间双神经网络摄像机标定法的仿真比较,证明了模糊化神经网络摄像机标定法的有效性。     

移动机器人足目标定方法

为构建完整的移动机器人视觉导航系统,提出了一种移动机器人足目标定方法．该方法以一个带有数个已知标记点的平面反射镜为中介,分别标定出平面镜坐标系与摄像机坐标系的欧氏变换关系、镜像坐标系与摄像机坐标系的欧氏变换关系、镜像坐标系与平面镜坐标系的欧氏变换关系及机器人坐标系与平面镜坐标系的欧氏变换关系,从而确定摄像机坐标系和移动机器人车体坐标系的欧氏变换关系,实现了移动机器人足目标定．实验结果表明,该方法简单、有效,无需昂贵的标定装置和复杂的标定过程,且可实现现场标定．