柔性加工系统中激光参量的数值化控制及界面设计

激光柔性加工是近几年兴起的一种先进制造技术，它结合了激光加工与柔性制造的特点，有很好的应用前景。在本论文中，讨论了与之相关的课题研究，其中包括：（1）激光器的稳定控制。包括激光器通讯方式的研究，底层驱动程序（VxD）的特点和开发应用，并给出了相关程序的解释。（2）激光器控制程序的开发。包括程序的设计思想、主要模块的功能和激光参数数值化控制的实现。（3）激光柔性加工系统控制软件的开发。包括软件的设计目标、主要功能、模块构成和软件易用性设计。（4）激光加工工艺试验。研究了主要的模具材料经过激光表面强化后粗糙度、材料组织、硬度以及耐磨性等主要力学性能的改善。薄板打筛孔主要分析了激光打孔的优势所在。

BDI Agent的人机智能结合方法

在网络遥操作中存在着由于操作者的操作负担过重或长时间操作而引起的误操作问题,提出以著名的BDIAgent模型为基础,通过引入中断机制,将反映操作者智能决策的操作目标、操作意图与BDIAgent推理产生的目标、意图进行结合的方法,为解决Agent智能的局限性和操作者的误操作问题,提供了一种人机接口方法,实现了人机智能结合.给出了中断的引入方法和操作者操作目标、操作意图中断响应原理,用形式化模型描述了人机智能决策选取目标和意图的过程.该人机智能结合方法在网络遥操作RoboCup中型足球机器人系统中得到了应用.

智能机器人分层系统中的人机交互

在非结构环境里工作的智能机器人,人智能的介入有时是必不可少的.本文研究了这类机器人系统人机接口某些问题,提出了人智能输入的分层输入原则,实时性原则和协调性原则,讨论了人机接口的结构和实现问题,给出了人机接口命令的一种格式,并提出了人机操作的实际例子.

移动机器人遥操作中力反馈技术的研究

在已有的遥操作系统中增加力反馈,通过计算移动机器人与周围障碍物之间的虚拟交互力,并将其映射到操纵杆上变成操作者可以感知的力,这样操作者能感觉到机器人与环境之间的作用力,从而有效地完成操作任务.实验结果表明该方法能够有效控制机器人行走,显示了在非结构性环境下临场感在增强人机交互能力方面的优越性.

面向任务的虚拟环境和人机交互方法研究

基于虚拟现实技术的人机交互方法为面向任务的机器人远程作业研究提供了新的思想和思路 ,增强了机器人系统的遥控作业能力 .本文对机器人系统中虚拟环境和人机交互方法研究进行了综述 ,对虚拟环境中的示教和遥操作进行了评析 ,并探讨了未来遥操作机器人系统作业的发展趋势

机器人插件作业的视觉导引方法研究

插件作业 (parts mating)是装配机器人的一项基本作业环节 .本文介绍了以双目立体视觉实现该作业的视觉导引方法 .该方法通过采用人机交互方式 ,借助于人的智慧 ,提高了图像特征提取和匹配的准确性和可靠性、可直观准确地给出插件作业的动作参数 ,克服了自动视觉计算复杂、鲁棒性差的缺点 ,适用于机器人遥操作作业 .实验表明 ,基于人机交互的机器人插件作业在立体视觉导引下是完全可行的

移动机器人人机互助行走监控方法研究及其实际应用

由于行走监控在移动机器人技术中的独特地位和作用，使得其问题解决路线与最终性能极大地影响着构成系统的实用性及用户接受程度．本文通过剖析行走监控同其他模块的内在联系，深入地讨论了研究此问题的必要性和困难所在．最后，结合一个实际应用系统，给出了行之有效的指导思想、实现策略和关键问题解决途径。

PASSIM卷接机组新型电控系统的设计与实现

PASSIM卷接机组原控制系统采用电路板进行逻辑控制,抗干扰性能差,故障率高,造成生产效率降低、原材料消耗增大、维修工作繁重等。为此,设计了一套新型卷接机组电气控制系统。该系统采用PLC进行过程控制,以工控机为上位机完成人机通信,采用交流伺服驱动,并通过高速信号处理专用系统完成重量检测控制及烟支质量检测功能;利用PROFIBUS、CAN及MPI多种总线方式完成各单元间的通讯,实现信号和数据间的传递和共享。改进后的PASSIM机组运行稳定可靠,采样速度快,实时性强,且维修方便。机组的有效作业率由85%左右提高到90%以上,降低了卷烟纸和烟丝等原材料的消耗。

Stress-strain fields and the effectiveness shear properties for three-phase composites with imperfect interface

Based on the 'average stress in the matrix' concept of Mori and Tanaka (:Mori, T., Tanaka, K., 1973. Average stress in matrix and average elastic energy of materials with misfitting inclusion. Acta Metall. 21, 571-580) a micromechanical model is presented for the prediction of the elastic fields in coated inclusion composites with imperfect interfaces. The solutions of the effective elastic moduli for this kind of composite are also obtained. In two kinds of composites with coated particulates and fibers, respectively, the interface imperfections are takes to the assumption that the interface displacement discontinues are linearly related to interface tractions like a spring layer of vanishing thickness. The resulting effective shear modulus for each material and the stress fields in the composite are presented under a transverse shear loading situation.

An experimental study on turbulent coherent structures near a sheared air-water interface

The turbulence structures near a sheared air-water interface were experimentally investigated with the hydrogen bubble visualization technique. Surface shear was imposed by an airflow over the water flow which was kept free from surface waves. Results show that the wind shear has the main influence on coherent structures under air-water interfaces. Low- and high- speed streaks form in the region close to the interface as a result of the imposed shear stress. When a certain airflow velocity is reached, "turbulent spots" appear randomly at low-speed streaks with some characteristics of hairpin vortices. At even higher shear rates, the flow near the interface is dominated primarily by intermittent bursting events. The coherent structures observed neat sheared air-water interfaces show qualitative similarities with those occurring in near-wall turbulence. However, a few distinctive phenomena were also observed, including the fluctuating thickness of the instantaneous boundary layer and vertical vortices in bursting processes, which appear to be associated with the characteristics of air-water interfaces.

Thermal-mechanical interface crack behaviour of a surface mount solder joint

The effect of thermal-mechanical loading on a surface mount assembly with interface cracks between the solder and the resistor and between the solder and the printed circuit board (PCB) was studied using a non-linear thermal finite element analysis. The thermal effect was taken as cooling from the solder eutectic temperature to room temperature. Mechanical loading at the ends of the PCB was also applied. The results showed that cooling had the effect of causing large residual shear displacement at the region near the interface cracks. The mechanical loading caused additional crack opening displacements. The analysis on the values of J-integral for the interface cracks showed that J-integral was approximately path independent, and that the effect of crack at the solder/PCB interface is much more serious than that between the component and solder.

Application of laser cladding technology to improve the interface of thermal barrier coatings

The present study is focused on improvement of the adhesion properties of the interface between plasma-sprayed coatings and substrates by laser cladding technology (LCT), Within the laser-clad layer there is a gradient distribution in chemical composition and mechanical properties that has been confirmed by SEM observation and microhardness measurement. The residual stress due to mismatches in thermal and mechanical properties between coatings and substrates can be markedly reduced and smoothed out. To examine the changes of microstructure and crack propagation in the coating and interface during loading, the three-point bending test has been carried out in SEM with a loading device. Analysis of the distribution of shear stress near the interface under loading has been made using the FEM code ANSYS, The experimental results show clearly that the interface adhesion can be improved with LCT pretreatment, and the capability of the interface to withstand the shear stress as well as to resist microcracking has been enhanced.

A Crack Perpendicular to the Bimaterial Interface in Finite Solid

The dislocation simulation method is used in this paper to derive the basic equations for a crack perpendicular to the bimaterial interface in a finite solid. The complete solutions to the problem, including the T stress and the stress intensity factors are obtained. The stress field characteristics are investigated in detail. It is found that when the crack is within a weaker material, the stress intensity factor is smaller than that in a homogeneous material and it decreases when the distance between the crack tip and interface decreases. When the crack is within a stiffer material, the stress intensity factor is larger than that in a homogeneous material and it increases when the distance between the crack tip and interface decreases. In both cases, the stress intensity factor will increase when the ratio of the size of a sample to the crack length decreases. A comparison of stress intensity factors between a finite problem and an infinite problem has been given also. The stress distribution ahead of the crack tip, which is near the interface, is shown in details and the T stress effect is considered.

Concentration distribution in solution crystal growth: effect of moving interface conditions

The linear diffusion-reaction theory with finite interface kinetics is employed to describe the dissolution and the growth processes. The results show that it is imperative to consider the effect of the moving interfaces on the concentration distribution at the growth interface for some cases. For small aspect ratio and small gravity magnitude, the dissolution and the growth interfaces must be treated as the moving boundaries within an angle range of 0 degrees < gamma < 50 degrees in this work. For large aspect ratio or large gravity magnitude, the effect of the moving interfaces on the concentration distribution at the growth interface can be neglected except for gamma < - 50 degrees.