用于微器件装配的微操作系统

微器件装配技术是微机械的关键技术之一,本文从微 器件装配系统的特性和功能出发,提出了一套用于微装配的微操作系统设计方案,并对系统 各个组成部分进行分析,介绍了系统实现的方法．     

微器件自动装配系统的定标和操纵策略

主要研究了自动微器件装配系统的定标技术和操纵策略两个问题.在加入了尺度因子优化步骤之后,一种基于Tsai两步法的自定标方法实现了亚微米级的定标精度,并且获得了更加可信的定标角度参数.这种定标方法应用于微器件装配系统中并可以实现高精度的微器件定位.除了精确定标之外,我们还应该选择合适的工作环境来控制粘附力的大小来提高微器件操纵成功率,选择合适的夹持和释放方式来提高微器件操纵效率和释放位置精度,选择一种安全简单的移动路径来缩短移动时间.实验表明,我们的自动微器件装配系统可以在10 s内完成一个器件的定位和移动操作,并实现数微米的释放位置精度.     

宏微结合的多机械手微装配机器人系统

为解决复杂组件装配中存在的并行操作、空间操作和多操作对象的难题,研制了一套基于显微视觉伺服的多机械手微装配机器人系统.该系统有6个机械手,每个机械手都由宏动模块、微动模块和末端夹持器组成.分别针对5种不同结构类型的零件,设计了5种异形零件夹持器.通过给镜头配置高精度的位移平台,实现了在30 mm×30 mm×30 mm的大操作空间内2μm精度的在线检测,可实现±9μm的装配精度.通过显微视觉反馈和力觉反馈相结合的策略,设计了过盈配合件的装配方法.使用该微装配机器人开展了微装配实验,实验结果表明该微装配机器人系统是可行的,基本能实现既定的装配要求.     

视觉反馈的微装配自动调焦系统

基于视觉反馈的微装配自动调焦系统由可调焦光学显微镜、CCD、图像采集卡、步进电机和齿轮减速传动机构等组成.它采用粗精组合式调焦算法,即使用Variance调焦函数结合优化爬山法进行粗调来确定聚焦目标区域,并应用梯度平方函数进行精调;最后用最小二乘法拟合得到焦平面位置.实验证明,该自动词焦方法具有响应速度快、精度高等特性,满足了微装配调焦对精度的要求.     

基于视觉的微装配软件系统

针对微小零件的装配,采用Visual C++开发平台,应用模块化的软件设计方法,引入示教编程方法,实现了微小零件复杂的装配过程。建立了电位移控制评价函数,实现了电位移台通信的自动连接。依据微装配过程控制流程策略,采用了"三层架构"式软件体系结构,实现了微装配控制系统。系统可针对不同形状及尺寸进行装配,精度可达5μm。     

微装配中零部件搜索方法

针对如何快速且准确地在微装配的显微视野中寻找到目标零部件,并获取目标零部件的全局视觉信息的问题,提出了一种基于显微视觉倍率切换的微装配零部件搜索机制.详细分析了如何确定自动搜索步长;论述了自动搜索策略的原理与过程:通过自动扫描目标平面,以准确识别出目标平面内的微零部件,有效地克服了大范围微装配中显微视觉范围远小于操作域的局限性,保证了微装配零部件目标始终呈现在不同显微倍率视野中,为微装配机器人的进一步操作奠定了视觉基础.实验结果表明:提出的搜索方法搜索成功率达到了95％,平均搜索时间为28 s.     

微装配机器人的控制软件设计

针对亚毫米级微型零件的装配精度和效率偏低的问题,构建了21自由度微装配机器人控制系统。首先简要介绍了其控制系统的硬件组成。接着将系统控制软件分解成相应的功能模块,并由这些软件模块组成二个控制阶段,以完成整个微装配过程。提出了一种通用的基于.NET框架的＂四层架构＂设计模式,简化了各软件模块的编写工作,重点讨论了各层的功能及实现细节。最后,成功地应用了所提出的设计方案构建了微装配系统,结果表明该控制系统极大的改善了装配精度和装配效率,能够满足微装配作业的要求。     

基于有限元分析的ICF靶半自动装配系统的微夹钳设计

根据惯性约束聚变(ICF)靶零件的特点,确定用于ICF靶半自动装配系统微夹钳的技术指标,并完成其结构设计.该微夹钳采用柔性铰链机构和压电陶瓷驱动,可根据需要更换不同形状和开口距离的夹口,以适应夹持不同靶零件.以压电陶瓷的2种极限参数为载荷,分析了微夹钳的张合量、应力分布、应变量,并采用非线性接触分析对夹持力和夹持效果进...     

微操作/微装配中微力觉的测量与控制技术研究现状综述

微力觉的测量与控制技术是微操作/微装配领域内的核心内容和难点课题,是满足微器件可靠操作与无损装配要求的重要技术保障之一.本文介绍了微操作/微装配机器人系统的典型框架,并对各分系统的研究要点做了分析与回顾.然后,从微力觉的特点、微力测量方法与传感器、微力觉控制三个方面对微力觉的测量与控制技术的发展现状进行了综述.着重介绍了近些年在远程微操作系统和微操作/微装配系统中微力觉控制的方法及核心研究内容的研究成果.在此基础上,提出了微力觉测量与控制亟待解决的一些关键问题,并对这些关键问题的解决方案进行了探讨.最后,对微力觉的发展前景和方向进行了展望.     

装配生产线集散式监控系统的研制

本文介绍了用于冰箱装配生产线的集散式监控系统，解决了集散式控制、异型计算机通信网络、生产线空间和功能上的直辖市平衡、远程监控 、故障诊断、容错能力和系统重组能力等CIMS中的基础问题，介绍了基于Petri网络理论的步进式方法。实现生产应用表明，该控制方案为实现车间级生产自动化提供了一个经济可行的途径。     

A semi-automatic system for edge tracking with snakes

Active contour models, or snakes, developed in (Kass et al. 1988), use a simple physical model to track edges in image sequences. Snakes as originally defined however, tend to shrink, stretch and slide back and forth in unwanted ways along a tracked edge and are also confused by multiple edges, always grabbing the nearest one. In this paper a semi-automatic system is presented that combines motion estimation techniques with snakes to overcome these problems. An algorithm is presented that uses a block matching technique to guide the endpoints of the snake, optical flow to push the snake in the direction of the underlying motion, followed by the traditional snake edge-fitting minimization process. We use this technique for tracking facial features of an actor for driving computer animated characters.     

A semi-automatic system for segmentation of cardiac M-mode images

Pixel classifiers are often adopted in pattern recognition as a suitable method for image segmentation. A common approach to the performance evaluation of classifier systems is based on the measurement of the classification errors and, at the same time, on the computational time. In general, multiclassifiers have proven to be more precise in the classification in many applications, but at the cost of a higher computational load. This paper analyzes different classifiers and proposes an evaluation of the classifiers in the case of semi-automatic processes with human interaction. Medical imaging is a typical application, where automatic or semi-automatic segmentation can be a valuable support to the diagnosis. The paper focuses on the segmentation of cardiac images of fruit flies (genetic model for analyzing human heart’s diseases). Analysis is based on M-modes, that are gray-level images derived from mono-dimensional projections of the video frames on a line. Segmentation of the M-mode images is provided by classifiers and integrated in a multiclassifier. A neural network classifier, a Bayesian classifier, and a classifier based on hidden Markov chains are joined by means of a Behavior Knowledge Space fusion rule. The comparative evaluation is discussed in terms of both accuracy and required time, in which the time to correct the classifier errors by means of human intervention is also taken into account.

Equipment technology for flexible and automated micro-assembly

Micro-assembly differs from conventional assembly in terms of the size and characteristics of the objects involved. As a result the requirements relating to handling precision are so high that it is often very difficult to achieve them with manual operations. These extremely challenging requirements usually relate to environmental conditions and adjustable gripper tools, frequently equipped with a range of sensors. The extensive automation of micro assembly is therefore desirable for both cost and performance.     

Modular architecture of the microfactories for automatic micro-assembly

The construction of a new generation of MEMS which includes micro-assembly steps in the current microfabrication process is a big challenge. It is necessary to develop new production means named micromanufacturing systems in order to perform these new assembly steps. The classical approach called “top-down” which consists in a functional analysis and a definition of the tasks sequences is insufficient for micromanufacturing systems. Indeed, the technical and physical constraints of the microworld (e.g. the adhesion phenomenon) must be taken into account in order to design reliable micromanufacturing systems. A new method of designing micromanufacturing systems is presented in this paper. Our approach combines the general “top-down” approach with a “bottom-up” approach which takes into account technical constraints. The method enables to build a modular architecture for micromanufacturing systems. In order to obtain this modular architecture, we have devised an original identification technique of modules and an association technique of modules. This work has been used to design the controller of an experimental robotic micro-assembly station.     

Development of the electric wheelchair hands-free semi-automatic control system using the surface-electromyogram of facial muscles

The goal of Human–Computer Interface (or called Human–Robot interface) research is to provide humans with a new communication channel that allows translating people’s intention states via a computer into performing specific actions. This paper presents a novel hands-free control system for controlling the electric wheelchair, which is based on Bio-signals just as surface electromyogram signals. The Bioelectric signals are picked up from facial muscles, then the Bio-signals are passed through an amplifier and a high pass filter. Motion control commands (Forward, Left, Right, Forward to the Right, Forward to the left and Stop) are classified by simple rule, and these commands are used for controlling the electric wheelchair. However, it is difficult to realize safety control and fine control using the biological signal only. In addition, we introduce the semi-automatic control system using the laser range scanner. In this paper, we report the introduction of our proposal systems and our experimental results.     

Design and implementation of a hardware-in-the-loop simulator for a semi-automatic guided missile system

Hardware in the loop (HIL) simulation based on modern digital signal processors is a cost-effective technology for the design and evaluation of various sophisticated weapon and industrial systems. In this article a HIL simulation is presented through the very complex problem of modernisation of the semi-automatic command to line of sight (SACLOS) missile system. The presented examples illustrate the importance of the HIL simulation technology for the cost-effective, non-destructive prototype development of such SACLOS systems. The key role of a flexible simulation platform consisting of 4 TMS320C40 digital signal processors for efficient real-time simulation of the implemented SACLOS subsystem models is also emphasised in this paper.     

城市食品安全体系智能溯源终端设计

为提高城市食品安全溯源体系信息化程度,提出一种智能溯源移动终端设计方法。针对溯源信息流程的特点,设计一种以ARM控制器为核心,集成条码技术、电子标签技术、无线网络通讯技术, GPS定位技术、嵌入式数据库技术的手持终端设备。通过软硬件的一体化协同设计,提高设备集成度,减少溯源流程中人工输入输出环节,在溯源信息载体与集成互连网技术和数据库技术的溯源平台之间建立桥梁和纽带。该设备在项目应用示范中工作稳定,方便实用,提高了城市食品溯源体系的效率。