模块化可重构足式仿生机器人设计

在应用仿生学原理和拓扑理论对足类生物骨骼结构进行简化和模块化分的基础上,开发了一套模块化可重构足式机器人系统,此套系统能够构造出多种不同构形的足式机器人,并且由于采用了均一化的设计,在一定程度上降低了生产成本。     

Kinematics and dynamics analysis of a quadruped walking robot with parallel leg mechanism

It is desired to require a walking robot for the elderly and the disabled to have large capacity,high stiffness,stability,etc.However,the existing walking robots cannot achieve these requirements because of the weight-payload ratio and simple function.Therefore,Improvement of enhancing capacity and functions of the walking robot is an important research issue.According to walking requirements and combining modularization and reconfigurable ideas,a quadruped/biped reconfigurable walking robot with parallel leg mechanism is proposed.The proposed robot can be used for both a biped and a quadruped walking robot.The kinematics and performance analysis of a 3-UPU parallel mechanism which is the basic leg mechanism of a quadruped walking robot are conducted and the structural parameters are optimized.The results show that performance of the walking robot is optimal when the circumradius R,r of the upper and lower platform of leg mechanism are 161.7 mm,57.7 mm,respectively.Based on the optimal results,the kinematics and dynamics of the quadruped walking robot in the static walking mode are derived with the application of parallel mechanism and influence coefficient theory,and the optimal coordination distribution of the dynamic load for the quadruped walking robot with over-determinate inputs is analyzed,which solves dynamic load coupling caused by the branches’ constraint of the robot in the walk process.Besides laying a theoretical foundation for development of the prototype,the kinematics and dynamics studies on the quadruped walking robot also boost the theoretical research of the quadruped walking and the practical applications of parallel mechanism.     

基于广义几何误差模型的微机器人精度分析

提出了一个用于微机器人精度分析的通用方法,该方法以广义几何误差的形式描述各种误差源对机器人本体产生的影响,通过任两座标系间的向后微分关系,利用运动学方程以及并联机构的环路特性,建立了微机器人的广义几何误差模型。基于此模型,对工作空间中的位姿误差进行了仿真分析,验证了该法的有效性。此方法虽然是针对微机器人,但可推广应用到一般并联机器人的误差建模和精度分析。     

可变形机器人协同变形方法

可变形机器人AMOEBA-I的主要特点是具有多种构形方式,但由于受地面条件等影响使得某些构形变换难以实现.为了减小变形阻力,增强机器人对环境的适应性,提出可变形机器人的协同变形方法.建立相应数学模型,分析机器人系统各部分在协同变形过程中的运动和力学特性,实现将变形阻力的一部分转化为变形的动力,完成5种特殊构形之间的相互变换.研究基于摄动分析方法的模型线性化方法,以减小计算复杂度.最后,给出可变形机器人协同变形性能评价指标,并通过仿真和试验验证协同变形方法的有效性,满足机器人变形需要.     

面向并联机器人驱动器故障的容错纠错方法研究

基于机构类型演化提出了一种具有驱动器故障容错功能的1TP+3TPRS型并联机器人的新结构;研究了机器人的机械系统容错重构策略;在位置反解的基础上导出了机器人的重构规划算法;对于退化机器人容错性能指标的研究,定义了容错空间影响因子,可以用来衡量机器人在发生故障后的容错操作能力;基于这个指标,提出容错并联机器人的结构参数优设计方法;通过模拟动平台按预期轨迹运动时某驱动器在不同时刻发生故障的情况,比较了退化机器人的工作状况,结果表明基于容错空间影响因子的结构参数优设计方法对于提高容错性能具有重要的意义。     

基于人工生命算法的并联机器人最优轨迹规划

基于机器人直纹面概念和人工生命算法,提出一种并联机器人位姿轨迹最优规划方法.应用计算几何中的三维直纹面生成原理,对机器人末端执行器的位置和姿态进行统一描述.考虑到机器人姿态直纹面面积及其变化率能够反映和评价机器人的运动学和动力学性能,通过求解等效角位移矢量在空间的运动轨迹形成的三维直纹曲面面积及其变化率,并将其作为泛函的泛函极值,同时考虑运动时机器人的灵活度,建立机器人位置和姿态轨迹优化的数学模型.采用人工生命优化算法对代表并联机器人位姿轨迹的高阶参数化空间曲线的参数进行优选,通过优化轨迹直纹曲面面积及其变化率和机器人的灵巧度,使并联机器人具有良好的运动学和动力学性能.最后以一三自由度球面并联机器人轨迹规划实例,验证所提出方法的可行性.     

可重构模块化工业机器人构形及其静力学分析

可重构模块化工业机器人是机器人学研究领域中兴起的一个新的研究方向,其核心和基础内容是可重构工业机器人的模块划分和模块组合运动规划。分析可重构模块化工业机器人的特点,以50kg负载工业机器人为例,介绍了工业机器人模块的划分,结合课题所涉及的具体实例分别对工业机器人的各个模块进行了详细的叙述。采用基于SolidWorks的三维建模和基于ANSYS的结构性能分析相结合的方法,完成50kg负载工业机器人本体的构建,实现了工业机器人的可重构化。     

Low/distortion on exterior surface of auto body and its correction method

Surface low/distortion is one of the most challenging surface deflections that have a great effect on the exterior appearance of automobiles.Most studies on surface distortion/deflection have focused o...     

Kinematic calibration of precise 6-DOF stewart platform-type positioning systems for radio telescope applications

The pose accuracy of a parallel robot is a function of the mobile platform posture. Thus, there is no a single value of the robot’s accuracy. In this paper, two novel methods for estimating the accuracy of parallel robots are presented. In the first method, the pose accuracy estimation is calculated by considering the propagation of each error, i.e., error variations are considered as a function of the actuator’s stroke. In the second method, it is considered that each actuator has a constant error at any stroke. Both methods can predict pose accuracy of precise robots at design stages, and/or can reduce calibration time of existing robots. An example of a six degree-of-freedom parallel manipulator is included to show the application of the proposed methods.     

四足并联腿步行机器人动力学

基于模块化和可重构理论,提出一种助老助残四足/两足可重构并联腿步行机器人。该机器人既可组合成两足步行机器人,亦可作为四足步行机器人使用。运用影响系数理论和虚功原理,对四足步行机器人静态步行时的摆动腿和机体机构进行动力学建模,导出摆动腿的动力学方程和机体机构超确定输入下的协调方程,按加权最小二乘法对四足并联腿步行机器人机体机构的动载进行最优协调分配,解决了机器人在行走过程中各分支运动约束而产生的动力耦合问题。     

基于虚设运动副的并联机器人静态误差建模与标定

基于并联机器人影响系数和虚位移原理,以一般空间并联机器人为例,通过虚设运动副,提出一种并联机器人静态误差建模与分析的通用新方法。该方法用于确定各个原始加工装配误差源对并联机器人末端位姿的独立影响,具有物理意义明确、建模分析便捷等优势。在此基础上,基于虚设运动副建立了3-P(4S)并联机器人各误差映射矩阵,并对该机器人开展了静态误差标定实验研究。实验结果表明,基于该方法标定后,3-P(4S)并联机器人输出定位误差最大值由0.585mm减小到0.142mm,标定后机器人定位精度明显提高,从而验证了该方法的有效性。     

基于虚拟样机的可重构模块化机器人动力学分析

根据给定的工作任务分析确定可重构模块化机器人的构型后,进行机器人的轨迹规划和变量求解;然后采用牛顿-欧拉方法,并借助MATLAB软件设计用户界面计算和导出各个关节模块的实时控制变量值的文件,并将其导入ADAMS软件中进行动力学分析和仿真。     

Development of reconfigurable machines

This paper summarizes our survey on the development of reconfigurable machines (RMs). The goals of this survey were to (i) clarify the needs and drivers to develop the RMs, (ii) define the academic and practical issues involved in the development of RMs, (iii) learn the state of the art of the R&D on design methodologies of the RMs, and (iv) identify future research directions, which benefit the manufacturing industries in short and long terms. The survey has concluded that reconfigurable manufacturing systems (RMSs) are advantageous in dealing with changes and uncertainties in the ever-changing environment; while RMs are essential components to implement an RMS. RMs should be designed to meet a variety of task requirements via its reconfigurability. It has been found that few existing RMs can achieve this objective. The survey has concluded that the obstacles of the development of RMs include (i) the difficulties to identify and generalize design requirements since an RM is application-oriented and the design requirements have to be defined from an actual application; and in fact, some requirements are very difficult to be quantified; (ii) the lacking of efficient automated robot programming tools despite that the robots are essential components for most of the RMs; (iii) the lack of effective technologies that can be used to support system reconfigurations; (iv) no international organization that serves for standardizing the modular components for manufacturing and assembly processes; (v) the lack of the effort in implementing a heterogeneous system consisting of different types of RMs. The survey has suggested some future research works to overcome these obstacles.     

基于虚拟样机技术的柔性并联机器人建模与仿真

基于虚拟样机原理,利用SAMCEF软件对柔性并联机器人进行运动学、动力学建模和仿真,为柔性并联机器人的分析和设计提供了一种新方法.该方法建模简单,可视化强,后处理功能强大,可用于验证其它建模方法的理论分析结果.首次提出一种基于SAMCEF软件的柔性并联机器人固有频率的计算方法,可迅速计算柔性并联机器人在整个运动周期中的各阶固有频率.     

Modeling and experiment of a morphing wing integrated with a trailing edge control actuation system

Morphing wing has attracted many research attention and effort in aircraft technology development because of its advantage in lift to draft ratio and flight performance.Morphing wing technology combine...     

模块化变形机器人非同构构形表达与计数

提出一种新型链式可重构模块机器人平台,该机器人平台具有手动可重构和自动变形的特点,介绍一种三模块变形机器人样机。组成机器人的单个模块可以简化为由模块本体、连接臂和偏置关节组成。模块的数量可以根据实际工作的需要进行选择,模块间的连接具有规则连接和非规则连接两种方式;同时,由连接模块的偏置关节的运动,模块间的相对位置可以改变。由于模块连接方式的不同和模块间相对位置的变化,变形机器人具有多种非同构构形;为此,根据模块的物理结构和邻接关系提出了用构形矩阵来表达机器人结构的拓扑信息,并在仿真环境下进行等效描述;提出基于组合计数原理的递归算法,用于多模块变形机器人的非同构构形的计数,并根据构形矩阵的拓扑信息对构形进行评价。最后根据仿真结果给出了一种三模块变形机器人样机对称构形的设计示例,验证了算法的可行性。     

一种新型9-3可重构并联机构的设计、拓扑特性与重构分析

可重构并联机构具有变自由度及变构型的优点,设计了一种零耦合度、含3条冗余支链的新型9-3可重构并联机构。基于方位特征方程的并联机构拓扑结构设计理论与方法,创建了并联机构拓扑分析的模块化公式,并解析了机构的拓扑特性。基于一种可转换主、从运动及锁合的变胞移动副,利用主动模式与从动模式,将9-3型可重构并联机构转换为6-3A和6-3B这两种构型,并计算了它们的拓扑指标。结果显示,它们的耦合度分别为0和1。利用锁合模式,将6-3A型并联机构进行重构,得到了5类少自由度并联机构。特别地,以一种三自由度重构构型为例,详细分析了其拓扑特性。     

A Review on Cable-driven Parallel Robots

Cable-driven parallel robots(CDPRs) are categorized as a type of parallel manipulators. In CDPRs, flexible cables are used to take the place of rigid links. The particular property of cables provides CDPRs several advantages, including larger workspaces, higher payload-to-weight ratio and lower manufacturing costs rather than rigid-link robots. In this paper, the history of the development of CDPRs is introduced and several successful latest application cases of CDPRs are presented. The theory development of CDPRs is introduced focusing on design, performance analysis and control theory. Research on CDPRs gains wide attention and is highly motivated by the modern engineering demand for large load capacity and workspace. A number of exciting advances in CDPRs are summarized in this paper since it is proposed in the 1980 s, which points to a fruitful future both in theory and application. In order to meet the increasing requirements of robot in different areas, future steps foresee more in-depth research and extension applications of CDPRs including intelligent control, composite materials, integrated and reconfigurable design.     

基于遗传算法的并联机器人运动学正解研究

运动学正解分析是对并联机器人其它性能进行分析的基础,也是并联机器人研究中的一个难点。本文采用遗传算法来求解并联机器人的运动学正解,并且利用灰色关联分析对求解结果进行了分组,得到了Stewart平台并联机器人的7组实解。实例表明该方法简单、方便、具有通用性,是求解并联机器人运动学问题的一种新策略。     

一种连续型肠道机器人的通过性研究与仿真

在仿真环境下研究一种线驱动连续型肠道机器人的通过性.这种机器人没有传统刚性机器人的刚性关节和连杆,无法利用传统D-H(Denavit-Hartenberg)法对其进行运动学分析.因此利用几何分析法提出了一种简练的运动学算法.采用医学上的肠道统计数据,基于Microsoft Visual C++6.0和OpenGL建立了肠道模型和机器人原理模型.在此基础上采用一种几何相交算法,对不同关节长度的机器人进行了肠道通过性研究与仿真,展示了这种连续型肠道机器人的运动能力,并对其通过肠道时的误差进行了分析.仿真结果验证了该算法的正确性并得出了机器人通过肠道的必要条件.