片状脆性材料拾放机械手控制系统设计与实现

针对质子交换膜燃料电池(PEMFC)膜电极的制备,提出一种用于拾放片状脆性材料的五自由度机械手,并重点研究其控制系统的设计与实现.为满足膜电极制造工艺中提出的精确力/位控制、精确对位和快速拾放的控制要求,提出基于运动模式切换和力/位双闭环控制策略,基于视觉对准的视觉纠姿系统和基于速度、加速度前馈的位置控制方法.这些控制策略和方法已成功运用于片状脆性材料拾放机械手的控制系统中,控制效果良好,亦可推广到集成电路(IC)制造装备等其他领域.     

集装箱喷漆机械手工作空间分析与仿真

对5自由度集装箱喷漆机械手建立D-H坐标系,通过齐次变换法得到其正运动学方程,利用蒙特卡洛方法对机械手工作空间进行仿真分析.结果表明,集装箱喷漆机械手工作空间分布在一平行于集装箱内表面的平面区域内,能够满足集装箱喷漆工艺的要求.蒙特卡洛法求解速度快,能够简单、直观、形象地描绘出机械手的工作空间.     

铲运机工作装置基本参数的求解方法

工作装置是铲运机的重要组成部分,铲运机的铲装、翻斗、举升以及卸料工况都是通过工作装置的相关运动来实现的。本文以典型的反转六杆机构为研究对象,建立了铲运机工作装置数学模型,求出在不同工作状况下工作机构基本性能参数。同时,作者对工作装置中的角度作了特殊的规定,使得求解公式具有比以往公式更好的合理性和通用性,而且易于编写成程序模块,为优化设计结果和性能评估提供了很大的方便。     

空间站转位机构末端效应器位姿设定试验方法研究

针对空间站转位机构末端效应器地面试验要求,提出采用并联机构实现执行器与适配器之间的六维空间位姿设定。首先,设计了6自由度并联机构,并对其机构构成和工作原理进行了阐述;其次对所设计并联机构的工作空间运动学及作动器与适配器的运动干涉特性进行了数学建模,最后,编制了基于柱坐标的机构工作空间搜索算法和基于空间几何的干涉检测算法,并运用MATLAB进行了仿真分析。仿真结果表明,所设计的并联机构其工作空间满足末端效应器位姿设定的范围要求,并联机构各分支作动器与末端效应器之间不会发生运动干涉,验证了该方法的有效性。     

一种组合机构机械手和它的应用

本文首先介绍了一种新型的组合机构机械手，然后举出了它在生产线中的应用。     

空间机械手末端位姿修正模型构建方法

为了有效减小空间机械手的末端位姿误差,通过分析误差来源,该文提出了基于BP神经网络的空间机械手末端位姿修正模型构建方法,设计了关节转角系统误差、关节转角随机误差、末端位姿系统误差和末端位姿随机误差共4类数据对该方法进行验证。仿真结果表明,该方法构建的修正模型是有效的,能够大幅提高末端位姿精度。     

Design schemes and comparison research of the end-effector of large space manipulator

The end-effector of the large space manipulator is employed to assist the manipulator in handling and manipulating large payloads on orbit.Currently,there are few researches about the end-effector,and the existing end-effectors have some disadvantages,such as poor misalignment tolerance capability and complex mechanical components.According to the end positioning errors and the residual vibration characters of the large space manipulators,two basic performance requirements of the end-effector which include the capabilities of misalignment tolerance and soft capture are proposed.And the end-effector should accommodate the following misalignments of the mechanical interface.The translation misalignments in axial and radial directions and the angular misalignments in roll,pitch and yaw are ±100 mm,100 mm,±10°,±15°,±15°,respectively.Seven end-effector schemes are presented and the capabilities of misalignment tolerance and soft capture are analyzed elementarily.The three fingers-three petals end-effector and the steel cable-snared end-effector are the most feasible schemes among the seven schemes,and they are designed in detail.The capabilities of misalignment tolerance and soft capture are validated and evaluated,through the experiment on the micro-gravity simulating device and the dynamic analysis in ADAMS software.The results show that the misalignment tolerance capabilities of these two schemes could satisfy the requirement.And the translation misalignment tolerances in axial and radial directions and the angular misalignment tolerances in roll,pitch and yaw of the steel cable-snared end-effector are 30mm,15mm,6°,3° and 3° larger than those of the three fingers-three petals end-effector,respectively.And the contact force of the steel cable-snared end-effector is smaller and smoother than that of the three fingers-three petals end-effector.The end-effector schemes and research methods are beneficial to the developments of the large space manipulator end-effctor and the space docking mechanism.     

车载式高空作业车平台调平机构

从介绍目前存在的车载式高空作业平台调平方式入手,分析比较适用于高空作业车各种调平机构的形式、性能和特点,指出了今后平台调平机构的发展趋势。     

液压挖掘机工作装置的动态强度仿真分析

针对在大型正铲液压挖掘机工作过程中工作装置的运动以及零件的应力分布问题,在多体动力学软件MSC.ADAMS中建立了刚-柔、机-液耦合的虚拟样机,其中动臂、斗杆是柔性体,其模态中性文件在ANSYS中生成,其余为刚性体,液压系统在ADAMS/Hydraulics中建立;对整机理论最大挖掘力开展了分析,进行了最大挖掘力普查,得到了工作装置在不同位置产生的最大挖掘力;在ADAMS中对其进行了运动学及动力学仿真,分析了其在相应约束以及负载状态下以最大挖掘力挖掘和以一定效率挖掘,举升工况时部件的应力应变.研究结果表明,该仿真模型比典型的工况方法更全面地反映了工作装置的运动状况和部件的强度状况,提高了计算精度和效率,可以为挖掘机结构设计优化提供较为可信的参考.     

质量平衡原理在机器人机械臂设计中的应用

机器人的机械臂设计对机器人的操作性能具有决定性的影响,本文运用质量平衡原理,利用关节驱动电机自身的质量对自行研制的YJP-1型双臂冗余度机器人的操作臂进行了优化设计,实验结果表明,该设计方法对减小机械臂动力系统的耦合惯量影响,减轻驱动电机负载具有良好的效果。     

A numerical method to calculate the Abbott parameters: A wear application

A numerical technique was proposed to plot the Abbott curve and to compute its associated parameters defined by the DIN 4776 and ISO 13565 norms. These parameters were then extended and applied to non-sigmoid Abbott curves. By studying the discretisation errors, we show that a minimum of 200 intercepts, with parabolic interpolations between discretised data profiles, have to be taken into consideration to calculate the parameters as accurately as possible. Experimental profiles were eroded by means of a numerical wear model, and it was shown that the Abbott parameters correlate well with the wear model parameters. Our numerical estimations of Abbott parameters were performed for electro-eroded, tool machined, polished, worn and sandblasted surfaces. Manual measures were compared with our algorithmic method and it was shown that the difference is lower than 1% for Mr1 and Mr2 Abbott parameters, but the numerical technique leads to a lower dispersion.     

机械手在制药生产线上的应用

介绍了机械手的设计方案和特点,对单片机最小系统模块、电源模块、时钟与复位模块、开关与键盘模块、显示模块和驱动模块进行了详细的阐述,同时说明了机械手在制药生产线上的实际应用,满足了制药企业的需求。     

起重机用减速器承载能力和选用方法探讨

本文对起重机减速器的承载能力和选用方法的分析表明,工作级别Ｍ１－Ｍ８中,其相邻级别按１．１２的比例折算功率稍大但比较接近于理论值,把Ｍ５的额定功率确定为连续工作状况的２倍则与理论值相差过大,因此,硬齿面齿轮减速器没有必要再去划分工作级别,通用的选用２方法同样适用于志重机减速器的选用。     

加工中心回转工作台部件的结构分析

介绍一种新开发的数控回转工作台的工作原理及结构特点     

6-SPS台体型并联机器人工作空间及转动能力研究

提出一种评价并联机器人实现位置和姿态能力的性能指标.选用局部坐标系和球面副的关节转角描述了动平台的位姿,探索了工作空间的边界,以动平台在工作空间内能实现的最小可达章动角评价并联机器人的转动能力,揭示出并联机器人工作空间体积及转动能力随机构结构尺寸的变化而变化的规律.     

基于随机概率的机器人工作空间及其面积求解

采用随机概率的蒙特卡罗方法得到了平面机器人的工作空间。由于此方法不用对机器人进行逆解计算，也不必直接对奇异值进行计算，所以非常适于工作空间边界曲线的绘制。本文的另一个目的在于扩展一种简单快速的方法，更有效地确定一般平面机器人工作空间的面积。由于工作空间是由一系列的直线或圆弧曲线构成的封闭图形，所以可以采用矢量法对边界点予以表示，并用窄矩形对面积进行近似计算。最后，对一个平面机构的实例进行了面积计算和比较分析。本文介绍的方法不但简单而且在工程中非常实用。     

超声多普勒流速测量中存储容量的压缩方法

介绍了多普勒频率单片机测量时的数据处理方法，即线性地址变换法。在存储容量有效压缩的基础上，进一步分析了采样数据，用软件实现可控时标，保证了测量精度。     

IPSW方法及其在变工况滚动轴承退化状态跟踪中的应用

感知获取的一维快变信号不仅受工况变化的影响,且无法避免地受到噪声干扰,此时传统的相空间曲变(PSW)方法提取的健康指数(HI)将无法胜任变工况下的滚动轴承退化趋势跟踪.针对这一问题,提出了改进的相空间曲变法(IPSW).从确保PSW分量的独立性及其信息最大化的角度出发,通过高维重构分量间的综合平均互信息局部极小化和互信...     

抽油井动液面回音信号的声速提取方法

在油井开采过程中,需要对油井的温度、压力、动液面等参数进行不定期测量以监控采油过程,其中动液面是一个重要的参数。目前常用的测量方法是次声波测量,在测量过程中声波的传播速度是一个关键参数,该文提出利用DSP的FFT方法来提取声速,从而提高测量精度。     

Tribology-related space mechanism anomalies and the newly constructed high-vacuum mechanism test facilities in NASDA

In the past many functional anomalies of mechanisms and mechanical components have been experienced on board spacecraft and their launch vehicles. Such anomalies sometimes lead to the total loss of the spacecraft. Among the major causes of mechanical anomalies, vacuum tribology-related malfunctions have received central attention in Japan due to the continued occurrence of spacecraft failures. Phenomena such as the increase of frictional forces between moving parts and the binding of metallic parts in high-vacuum environments are sometimes very difficult to examine in full scale on the ground, and only limited prototype verification is conducted in orbit. Responding to the strong need for the improvement of space mechanism and tribology research work, integrated multiple high-vacuum mechanism test facilities were constructed in NASDA Tsukuba Space Center in 1998. These facilities are intended to provide fundamental data on the performance of mechanical components and materials in high vacuum for validating space mechanism designs. One of the facilities also makes possible the examination of combined environmental factors, such as electron beams, ultraviolet radiation, atomic oxygen and temperature, for mechanisms and materials. This paper introduces typical features of the space-based mechanism functional anomalies and describes the new test facilities.