Bilateral prediction and intersection calculation autofocus method for automated microscopy

In this paper, a bilateral prediction and intersection calculation autofocus method for automated microscopy, which obtains the in‐focus position by calculating the intersection of the predicted left and right focus measure curves located respectively in the left and right sides of the peak position of the focus measure curve, is proposed and performed. According to the autofocus method, the area including the peak position of the focus measure curve and its left and right neighbourhoods should be determined firstly, and the left and right neighbourhoods are considered as the left and right sampling areas. The left and right focus measure curves are predicted by appropriate predicting models according to the two sample sequences, which comprise the focus values by evaluating the sampled images in the left sampling area and right sampling area, respectively and their corresponding sampling positions. The intersection of the predicted left and right focus measure curves is calculated and can be considered as the in‐focus position. The autofocus can be realized by moving the focus plane of the microscope to the intersection of the predicted left and right focus measure curves. The proposed bilateral prediction and intersection calculation autofocus method is experimentally verified in an automated light microscopy for implementing microassembly and micromanipulation. The theoretical analyses have shown that the proposed bilateral prediction and intersection calculation autofocus method can not only effectively avoid the principle error caused by assuming the symmetrical focus measure curve in the autofocus methods based on curve fitting, but also eliminate the possible waver search near the peak position in the modified fast climbing servo method. The experimental results have shown that the proposed bilateral prediction and intersection calculation autofocus method possesses the merits as follows: (1) the focusing accuracy is high and slightly affected by the sampling step size and (2) the focusing speed is higher than those of the 7‐point hill‐climbing search method and the quadratic curve fitting method with a determinate focusing accuracy.     

基于微装配领域的微操作机器人系统研究

微装配已成为制造业遇到的新问题,制约着微机电行业的发展。文中对用于微装配领域的微操作机器人系统进行了系统的研究。提出了微操作机器人机构的选型准则,介绍了控制系统结构框图以及补偿方法、显微成像系统的结构,以及微夹持器设计中存在的若干问题。     

微型零件胶粘接的微装配技术

微型零件的胶粘接技术是微装配中一种重要的联接技术，用于微小型产品的制造。本文介绍了微型零件的胶粘接技术及其所研制开发的用于胶粘接的微装配机器人系统，对微型直线电机导轨的胶粘接进行了说明，分析了胶粘接过程中可能出现的问题，提出了基于视觉图象对微型零件胶接过程的检测方法，通过图象处理测量胶滴的点样位置和大小，以确保胶粘接的质量。     

基于LTCC微波多层基板的双面微组装技术研究

传统的微波组件通常在低温共烧陶瓷(LTCC)微波多层基板上单面组装裸芯片和片式元器件,组装密度难以进一步提高.文中采用了LTCC微波多层基板双面微组装技术以提高组装密度,重点研究了高精度芯片贴装技术和芯片金丝键合技术,实现了LTCC微波多层基板双面高精度芯片贴装和金丝键合,大大提高了微波组件组装密度.实验结果表明:裸芯片的双面贴装精度均达到了±20 μm;双面金丝键合强度(破坏性拉力)均大于5 g,满足国军标要求.     

Modeling of Micromanipulation Robot in Virtual Environment

Micromanipulation has been recognized to be very difficult due to the inefficiency of traditional micromanipulation methods. The paper present a general framework for micromanipulation robot based on virtual reality technology.The significance of introducing virtual reality into micromanipulation is analyzed,and the current research in this field is reviewed. Based on this,we propose a micromanipulation system that integrates virtual environment with vision feedback and force feedback.The system realizes vision close-loop control and force close-loop control to enhance the performance of micromanipulation device.A graphics modelling method is proposed for a microassembly task. Hardware and software implementation is described and discussion about the research is presented.     

A Supervisory Wafer-Level 3D Microassembly System for Hybrid MEMS Fabrication

Hybrid MEMS (microelectromechanical systems) integrate solid-state ICs with MEMS sensors and actuators. It is widely believed that such systems will bring fundamental technological impacts and significant social benefits. Hybrid MEMS manufacturing requires the development of new fabrication, packaging and interconnection technologies in which microassembly plays a critical role. Microassembly is the assembly of objects with microscale and/or mesoscale features under microscale tolerances. It integrates techniques from many different areas such as robotics, computer vision, microfabrication and surface science. This paper studies the design and implementation of microassembly systems through the introduction of a supervisory microassembly workcell. This workcell is developed for 3D assembly of large numbers of micromachined thin metal parts into DRIE (deep reactive ion etching) etched holes in silicon wafers. It overcomes a major limitation of current MEMS fabrication techniques by allowing the use of incompatiable materials and fabrication processes to build complex-shaped 3D MEMS structures. The system is able to perform reliable and efficient wafer-level microassembly operations within a supervisory framework. Microassembly brings new and unique issues to robotics research. The major components of microassembly systems are analyzed. Results on micromanipulator design, illumination modeling and control, and microgripper design are presented.     

基于实体模型的虚拟微装配视觉伺服研究

微装配的主要问题是装配的器件小,装配精度高,一般用显微镜作为视觉传感器对装配运动进行控制。在大放大倍数下,显微镜的视场和景深很小,这时操作对象和操作工具就不会同时处在焦平面内,使得图像模糊,操作很难完成。利用显微镜的聚焦理论,提取对象的三维信息,构造对象的实体模型,使微装配在虚拟环境中进行,而实际环境只起监视的作用,当对象和工具不动时,虚拟操作环境不变化,而当操作对象和工具位置变化时,重构三维环境,使得虚拟环境和实际环境具有严格的位置对应关系。试验和仿真结果表明,该方法可以克服物体在显微镜下的失焦问题,而且操作方便。     

一种MEMS自动微装配机器人

介绍用于MEMS自动微装配的机器人系统的构成,讨论组成该系统的若干关键技术,包括宏/微精密定位技术、显微视觉系统、微夹持器的设计、系统的标定以及装配策略．集成各单元技术,以外径＜2 mm的微行星齿轮减速器为示范装配对象,研制能够完成微装配任务的微装配机器人．融合显微视觉和力信息,采用相应的装配策略,在2．5 min内,实现难度最大的3个行星齿轮的自动装配．     

毫米级全方位微机器人结构设计与控制对运动精度的影响研究

运动精度是微操作机器人的一个重要参数。针对一种用于微装配操作的毫米级全方位微机器人,分析了影响其运动精度的两个重要方面,即结构设计与控制。分析了结构设计方面的优点和不足,主要涉及传动系统、轮子的安装等。控制方面涉及路径规划和驱动器电磁微马达等。针对微机器人直线运动的非线性问题,提出了对工作区域进行分区的路径规划控制方法。针对电磁微马达的结构特点,提出了矢量合成、力矩自平衡等特殊的控制方法和思想,将微机器人步进运动精度提高了3倍。应用微机器人进行的微装配实验证明了以上方法的有效性。     

基于显微视觉的MEMS微装配系统研究

提出一种基于显微视觉伺服控制的MEMS器件微装配系统设计方案,描述了系统样机及关键技术模块的研制方案。以微型光谱分析仪极板粘接为示范应用开展了实验研究,表明该系统适用于典型MEMS芯片的微对准和封装研究。