Extreme reaches and maximal reachable workspace for rotary tools mounted on a Stewart platform manipulator

Abstract

A new type of problem associated with the extreme reaches of the Stewart platform manipulator is dealt with in this paper. Given a specified orientation of the tool axis, the problem involves finding the extreme distance that the tool bit mounted on the mobile platform can reach from its home position along any specified direction. During the motion, the mobile platform is allowed to be rotated about the tool axis to adjust the configuration of the driving mechanism to prevent premature activation of the kinematic constraints. A numerical optimization algorithm based on the concept of the cyclic coordinate descent method is developed for solving this problem, in which all three types of kinematic constraints, namely the actuator stroke constraint, the passive joint limitations, and the link interference conditions, have been taken into account. In addition, a numerical example is presented to demonstrate the ability of the proposed method to find the optimal reachable workspace of the robot.     

空调产品结构设计间隙检查系统开发

随着企业的产品日益向高档化、精致化发展,出于外观、运行平稳性、产品寿命等方面的考虑,对产品设计中的配合间隙控制提出了越来越高的要求。针对空调行业的应用,利用Pro/TOOLKIT二次开发技术,研发出一套高效的基于Pro/E平台的产品间隙控制系统,实现设计间隙检查表自动输出和更新,达到了减少设计重复工作、提高产品开发效率的目的。     

Algorithm based decision support system for the concerted selection of equipment in machining/assembly cells

Equipment selection plays a major role in the performance of machining/assembly cells. Based on analytical algorithms, a decision support system (DSS) is developed to select machining centres and robots concurrently from the milieu available in the marketplace. The DSS evaluates the design and geometry of the mating parts that are to be processed and assembled by the cell. Accordingly, it recommends the machining centre and robot that maximize the cell's performance subject to various operational and budget constraints.     

冲击台机械振实钨粉的实验研究

本文介绍了细颗粒钨粉在凸轮式冲击台上的振实实验,得出了粒度在2μm的细颗粒钨粉在不同振动参数下的振实密度.通过振动参数优化,使钨粉的最高振实密度达到了6.04g/cm3,从而满足了钨粉冷等静压的工艺要求,且钨粉粒度组成未发生明显变化,从而说明通过冲击台能够实现钨粉的机械振实及振动装料.     

7t升降平台车电气硬件的设

对7t升降平台车提出了一种以德国IFM移动控制系统CR0200为核心的电气硬件设计方案，并对主要控制硬件进行了选型，指出了设计中应注意的问题。为该类型车辆的电气硬件设计提供了很好的参考借鉴。     

Does genre type influence choice of video platform? A study of college student use of internet and television for specific video genres

With the introduction of multichannel video programming distributors and different types of video platforms, consumers have more choices of channels and platforms than ever. Specifically, the present study focuses on television and the Internet as video platforms.     

压缩机试机平台环氧砂浆锚固地脚螺栓技术

介绍了空气压缩机试机平台采用环氧砂浆锚固地脚螺栓的设计与施工方法,该法可广泛应用于机械设备的安装工程,能取得提高工程质量、加快工程进度和节约原材料的效果.     

合宁铁路滁河大桥137m钢混结合梁架设施工技术

介绍了合宁铁路滁河大桥137 m钢混结合梁架设的总体施工方案和施工步骤,具体阐述了现场平面布置、操作平台搭设、水中栈桥施工、行走龙门吊的安装等工艺和方法,并对机械配置、材料投入、人员组织作了说明,对类似工程具有一定指导意义。     

公共服务平台对轻纺行业发展的影响

简述了纺织和服装行业背景及发展趋势,阐述了轻纺行业建设公共服务平台的作用与意义,提出了建立行业公共服务平台的策略;打造集公益性、专业性、综合性于一体的公共服务平台,缩短采购与销售中间环节,降低成本,提高行业竞争力是其主旨。     

机载光电稳定平台润滑

根据机载光电稳定平台结构形式及使用环境,指出油脂润滑是稳定平台最佳润滑方式.通过对比平台轴承润滑前后的阻力矩差异,并用MATLAB作为工具分析该阻力矩对稳定精度影响情况,给出光电稳定平台对润滑脂性能要求和选用原则.