基于二值投影的PCB元件安装缺陷检测算法研究

研究分析了适用于AOI设备的PCB表面安装元件的缺陷检测算法.使用二值投影分析方法对2种元件类型的缺陷检测方法进行了研究,包括针对贴片电阻电容类型的chip元件和集成电路芯片类型的IC元件的缺陷检测方法.使用VC++6.0编写MFC程序实现算法,并制作了各种元件图像进行实验测试.实验结果表明,提出的方法能够快速有效的对两种类型的元件安装缺陷进行检测.     

多通道超声系统在管道内检测中的应用

多通道超声自动检测是管道腐蚀内检测的关键技术。根据管道内检测的要求,研制了具有20个探头的数字式多通道超声管道内检测系统。检测系统采用主从结构,检测板卡通过PCI总线与嵌入式计算机通信,并利用高速切换开关扩展通道数。超声回波信号处理采用Burg最大熵谱估计法,得到管道壁厚数据。经标准实验管段检测证明,检测系统能够检测管道内外腐蚀缺陷,数据采集、处理、存储及图像显示满足管道内检测要求,应用前景较好。     

基于 ADSP-2181 的 PCB标志定位系统

结合当前电子技术和图像处理技术的最新发展,设计了一种采用ADSP-2181数字信号处理器建构的图像检测定位的硬件平台,以满足图像检测的工业应用需要。运用并行数据流的分析方法系统论证了ADSP-2181作为图像检测系统核心处理器方案,提出了系统的数据流模型和控制模型,并以此设计实现了一个较高性能的硬件系统,具有视频图像获取、实时显示、图像处理和图像检测等多种功能。从PCB自动检测的标志识别及定位的需要出发,提出了适合硬件处理的Hough变换算法进行PCB圆形定位标志的检测,并给出了实验结果。     

Nondestructive evaluation sensor fusion with autonomous robotic system for civil infrastructure inspection

Civil infrastructure inspection is crucial to maintaining the quality of that infrastructure, which has a great impact on the economy. Performing this inspection is costly work that requires workers to be trained on how to use varying technologies, which can be error prone when performed manually and can result in damage to the infrastructure in some cases. For this reason, nondestructive evaluation (NDE) sensors are preferred for civil infrastructure inspection as they can perform the necessary inspection without damaging the infrastructure. In this paper, we develop a fully autonomous robotic system capable of real‐time data collection and quasi‐real‐time data processing. The robotic system is equipped with several NDE sensors that allow for a sensor fusion method to be developed that successfully minimizes inspection time while performing adequate inspection of areas that require more in‐depth data to be collected. A detailed discussion of the inspection framework developed for this robotic system, and the dual navigation modes for both indoor and outdoor autonomous navigation is presented. The developed robotic system is deployed to inspect several infrastructures (e.g., parking garages, bridges) at and near by the University of Nevada, Reno campus.     

Optimal inspection interval for a k-out-of-n system with non-identical components

In this paper, we develop a continuous-time discrete-state model for periodic inspection of a k-out-of-n cold-standby system with non-identical components. A perfect switching system detects the components’ failures, and the failed component(s) are repaired during the next inspection interval, and then added to the standby queue. The system can be in different states depending on the combination of working components and the order of the components on the standby queue at the beginning of an inspection interval. We present a matrix-based approach to determine the system states and calculate the system-states transition probabilities and the transition matrix. We calculate the expected total cost of the inspection intervals by determining the system state at the beginning and end of each inspection interval and calculating the inspection cost matrix. The expected total inspection cost consists of the system downtime cost, components repair cost, system repair cost, and system inspection costs. Finally, we minimize the system’s expected total cost by determining the system’s optimal inspection interval. The results show that determining the optimal inspection interval decreases the system's total inspection interval cost up to 60 % in comparison with the cases when the inspection interval is selected arbitrarily.     

海量数据流环境下自动化巡检平台开发与实现

自动化巡检平台是智能处理数据的崭新手段,当代信息社会不断产生大量数据流,为提升数据巡检性能,开发一种海量数据流环境下自动化巡检平台。数据采集层核心是Flume NG技术,包括Source、Channel、Sink组件,完成数据采集与传输;数据挖掘层利用数据挖掘过程模型、代码生成引擎、数据挖掘组件模型以及MapReduce执行框架等技术挖掘海量数据,获取自动化巡检结果;巡检结果在功能展示层通过B/S系统展现。仿真实验结果显示:海量数据环境下,平台查全率与查准率始终高于95%,巡检结果与实际情况一致,是一种可靠的海量数据自动化巡检平台。     

Inspection of the machined surfaces using manufacturing data

Accuracy of complex machined parts is usually estimated using coordinate measurement machines. The inspection results can be used to control or monitor a production system. Traditional inspection process of a machined surface commonly compares the resulting manufactured surface with the CAD-model or the nominal designed surface. Although, the result of this CAD-based inspection can be used to accept or reject the machined part, it does not provide the correct information required to study the machining errors and their behaviour. This paper presents a methodology to inspect a machined surface directly based on its actual CAM geometric model. The presented CAM-based inspection methodology can be used to model and understand the real machining errors, which can be utilized for process control, design for manufacturing or closed-loop machining.     

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IMAQ的印刷电路板电子元件缺件检测

提出了基于IMAQ Vision Assistant的印刷电路板上电子元件缺件检测方法。该方法首先对被检测的印刷电路板图像进行校正,然后主要利用IMAQ Vision Assistant的模板匹配函数实现对印刷电路板上电子元件缺件的检测。文中给出了应用实例,结果表明该方法能有效地检测出印刷电路板上电子元件缺件缺陷。     

飞机表面检查机器人系统研究

研究了飞机表面检查机器人系统结构及相关关键技术，提出了针对非对称异型飞机表面爬行机器人的总体结构和关键部件，对机器人作业过程中的吸附、运动及检测功能进行了分析，并给出了解决方案。研究了基于轨迹线性化理论的机器人路径跟踪控制算法，并对基于视觉的飞机铆钉裂纹缺陷检测与识别方法。试验结果验证了算法的有效性，为飞机蒙皮铆钉缺陷的自动在线检测提供了可行的途径。     

基于蛇形机器人桥梁缆索无损检测系统的研究

基于桥梁缆索无损检测的特殊性,且针对目前桥梁缆索检测智能化的需要,介绍了一种新型的检测系统,即基于桥梁缆索检测的蛇形机器人.此蛇形机器人具有较大的自由度,有非常好的环境适应能力.在分析蛇形机器人的本体结构特点和运动机理的基础上,并根据桥梁缆索的特性,研究了基于蛇形的器人桥梁缆索的无损检测系统.通过实验证明:此无损检测系...     

Optimal non-periodic inspection scheme for a multi-component repairable system using A search algorithm

This paper proposes an approach for finding an optimal non-periodic inspection scheme on a finite time horizon for a multi-component repairable system. The system consists of several components, each of which is subjected to soft failure. Soft failures of each component do not cause the system to stop functioning, but increase the system operating costs and are detected only if inspection is performed. Thus, the system is inspected at the scheduled inspection instances and if any of its components is found to have failed, the failed component is minimally repaired. The system’s expected total cost associated with a given inspection scheme includes inspection costs, repair costs, and the penalty costs that are incurred due to the time delay between the actual occurrence of a soft failure of the components and its detection at an inspection. The objective is to determine the optimal inspection scheme which minimizes system’s expected total cost.     

An on‐line grid‐gaps inspection system for electron‐gun manufacturing

An on‐line grid gaps inspection system (GGIS) for color‐CRT electron‐gun manufacturing has been developed. The measuring principle is based on the digital‐image‐processing technique and incorporates a design of stepping motor motion control. By utilizing the arrangement of stepping path image processing, the measurements for different types of guns and for different gaps on a gun can be effectively executed with higher resolution, and are easily implemented for the purposes of on‐line inspection and statistical quality control. Experimental results show that the system resolution is about 8.5–10 μm and the on‐line inspection index has been improved to about 120 pieces/hour.     

Automated visual inspection: A tutorial

This article introduces the topic of automated visual inspection (AVI) as a subset of machine vision. The components of a generic AVI system will be presented and current applications of AVI systems will be discussed. Specifically, the applications of automated dimension verification, bare printed circuit board inspection, stuffed printed circuit board inspection and component identification using color technology will be covered in some detail.     

Upper-body haptic system for snake robot teleoperation in pipelines

Snake robots have shown a great potential for operations in confined workplaces that are less accessible or dangerous to human workers, such as the in-pipe inspection. However, the snake robot teleoperation remains a nontrivial task due to the unique locomotion mechanism (e.g., helical motion) and the constraints of the workplaces including the low visibility and indistinguishable features. Most snake robot feedback systems are based on the live camera view only. It is hard for the human operator to develop a correct spatial understanding of the remote workplace, leading to problems such as disorientation and motion sickness in snake robot teleoperation. This study designs and evaluates an innovative haptic assistant system for snake robot teleoperation in the in-pipe inspection. An upper-body haptic suit with 40 vibrators on both the front and back sides of the human operator was developed to generate haptic feedback corresponding to the bottom and up sides of the snake robot, transferring the egocentric sensation of the snake robot to the human operator. A human-subject experiment (n = 31) was performed to evaluate the efficacy of the developed system. The results indicate that the proposed haptic assistant system outperformed other feedback systems in terms of both task performance and subjective workload and motion sickness evaluations. It inspires new control and feedback designs for the future snake robot in industrial operations.     

钢板表面缺陷在线视觉检测系统研究

本文设计了一套智能无损检测系统以实现对钢板表面缺陷的在线检测.检测系统由新型LED光源,明暗域结合成像光学系统、高速高分辨率线阵CCD器件、FPGA嵌入式处理系统和缺陷自动分类子系统等组成.系统对钢板表面的气泡、夹杂、结疤、划伤和压痕等主要缺陷进行无损检测,并基于Bayes决策理论,实现缺陷的自动分类功能.本系统在实验室检测指标为:宽度最大为1 800 mm,运行速度不大于1.5 m/s,振动幅度小于1 mm,横纵向检测分辨率为0.8 mm×0.8 mm,尺寸检测误差不大于1 mm.     

矿井提升机钢丝绳在线无损检测系统的设计及应用

介绍了钢丝绳弱磁检测原理,阐述了矿井提升机钢丝绳在线无损检测系统的构成及工作原理。应用结果表明,该系统能够精确地检测出矿井提升机钢丝绳的内、外断丝及损伤状况,检测效率高,且有效节约了用绳成本,大大降低了检测能耗。     

面向地下电缆沟智能巡检机器人的紧耦合SLAM系统

地下电缆沟的日常巡检劳动强度大,且存在危险隐患,是城市电力系统保持稳定工作亟需解决的问题,采用智能巡检机器人系统是解决这一问题的趋势。同步定位和实时地图的构建是地下电缆沟机器人自主巡检的前提。地下电缆沟等场景具有底纹理、结构化、路面平整度情况复杂、GPS信号差等场景特征,巡检机器人对该类结构化场景进行建图时,会出现地图退化和定位精度下降的现象。针对上述问题设计了一种基于多传感器的SLAM系统,融合了二维激光雷达、惯性测量单元、轮式里程计等多种传感器数据,通过自适应初始化对机器人里程计进行优化。针对不同路面平整度下的相邻激光关键帧匹配误差,设计了一种自适应帧间配准方法进行校正。现场试验表明,在路况复杂的地下电缆沟场景中,该方法比现有方法的地图退化率和定位误差平均分别降低了7.42%和8.73%,具有明显的工程应用价值。     

A vision system for on‐line inspection of CRT electron‐gun grid gaps

Abstract— A high‐resolution vision system for on‐line measurements of color CRT electron‐gun (E‐gun) grid gaps has been developed. The measurement principle is based on a digital image‐processing technique combined with a multi‐path imaging system. By utilizing the arrangement of multi‐path image processing, the measurements for different types of guns and for different gaps on a gun can be effectively executed with higher resolution. The purposes of on‐line inspection and statistical quality control are also easily implemented. Experiments were executed in the production line of a 15‐in. monitor, and the experimental results show that the system resolution is about 8.5–10 μm and the on‐line inspection index is about 300 pcs/hour.