平面全柔性3-DOF过驱动并联机构的最优综合

以设计全柔性多自由度过驱动并联机构为目标,研究了平面3-DOF 4RRR过驱动并联机构的最优综合问题．从一般四分支3-DOF平面并联机构出发,建立了机构的运动学模型;给出了机构的4种可能拓扑结构分类,对不同拓扑结构类型机构的运动学和力学性能进行了分析比较．建立了并联机构全工作空间操作性改善优化模型,采用遗传算法进行优化设计并给出了实例,根据优化实例的结果设计制造了平面全柔性三自由度过驱动并联机构．以上方法对其它全柔性并联机构的优化设计具有参考价值．     

基于3-PRC并联机构三维雕刻机动力学分析

以空间三平移并联机构为研究对象,采用旋量理论分析该机构动平台末端约束螺旋,3个转动自由度都被约束,得末端输出运动为三平移.由机构杆件的几何约束关系建立运动方程,求解出机构支链的运动一阶影响系数和二阶综合影响系数.采用凯恩方程建立机构动力学方程,将机构所受外力和惯性力转化为广义主动力和广义惯性力.用ADAMS软件对机构的...     

基于边界元法的平面运动并联机构静力学解析

针对混联运动机床开发中所采用的2 自由度平面运动并联机构部分进行了深入的研究．介绍了该平面 运动并联机构的组成,推导了并联机构的运动学正、逆解求解公式,求解了该机构的被动关节．基于边界元法对该 机构的受力情况进行了建模和解析,给出了每个杆件的受力情况．通过ADAMS 仿真验证了求解的正确性,为该机 构的设计开发奠定了基础．本文的分析方法也为并联机构的静力学解析提供了新的思路和方法．     

一类含有虚拟转轴的新型摇摆台构型综合与分析

为满足大型重载运动模拟对承载能力和载物空间等方面的要求,基于运动链等效替换法和并联机构转轴存在条件,综合出一类具有虚拟转轴的新型摇摆台机构.运用螺旋系约束判别方法分析了摇摆台机构的结构特征和自由度性质,在输入选取的基础上,运用螺旋理论建立了此类机构具有代表性的2-RPR-RRRAU-III-E+2-SPU的运动学和动力学模型,并通过数值算例对一种具有工程应用前景的构型进行了分析.该机构不仅具有大载物空间,而且可实现静载平衡,可用于大型重载运动模拟台.     

并联机器人机构的虚拟样机运动仿真实验研究

以先进制造装备中的机器人工作台为应用背景,研究一种具有四个自由度的新型并联机器人机构。对这种机构的结构作了简要介绍,对其运动特性和自由度作了理论分析和计算。运用虚拟样机技术,在ADAMS软件平台上构建该并联机器人机构模型。按照机构的结构几何尺寸计算各转动副的位置坐标,创建连杆等零件和各转动副,设定驱动副和初速度以及进行运动仿真实验。对仿真结果进行分析。实验和分析结果证明理论分析方法是正确的。此外还说明,完全可以运用ADAMS软件完成并联机构的运动特性分析虚拟样机实验,为并联机构的结构综合提供了一种新的实验方法。     

基于符号的机构概念运动模型

基于功能符号“三位一体”．陛提出了面向概念设计的机构运动模型表示方法;给出了功能语义蕴涵的运动变换约束和运动关系约束;通过功能符号形式化描述建立分层次的机构概念运动模型,实现对计算机辅助概念运动设计的支持．     

4-RP(RR)R并联机器人运动仿真

该文给出一个新型的少自由度并联机器人机构4-RP（RR）R的动态仿真。文中对此机构进行了反解分析,确立了此机构运动平台的位置输出与移动副输入及各空间顶点位置的关系。在此基础上,利用Matlab软件模拟出实物动态图,并对利用几何分析法做出的速度曲线、加速度曲线与利用虚设影响系数法求出的速度曲线、加速度曲线进行分析比较,进一步说明了机构本身的运动特性,以及虚设影响系数法对少自由度并联机器人机构4-RP（RR）R求解的正确性。     

基于螺旋理论的水下机器人矢量推进球面并联机构的运动学建模

为设计结构简单、具备旋转运动传递和空间姿态调整双重功能的水下机器人推进机构,采用构造过约束并联机构的方法设计了一种3自由度球面并联矢量推进机构.基于螺旋理论构建了机构的拓扑结构模型,分析了机构的运动特性,计算了机构的位姿正、逆解.在闭链约束方程的基础上运用矢量代数法推导出了机构的雅可比矩阵.利用特征结构配置的解耦法建立了机构速度和加速度的解析模型,并进行了相应的数值算例分析,计算了机构的运动学正、逆解,得到了可达工作空间,并用仿真软件Adams验证了数值计算方法的正确性.设计的矢量推进机构具有较大的偏转范围.     

耦合型3自由度并联稳定平台机构及其运动特征

基于舰船摇荡运动的耦合特征,采用耦合型3-SRR/SRU 3自由度并联机构作为舰载稳定平台机构,实现了稳定平台三轴驱动、动平台五轴联动补偿的目标．运用螺旋理论分析了机构的自由度和运动特征, 并讨论了输入关节选取的合理性|采用坐标等效运动的方法,建立机构耦合运动约束方程,得到了位置解及工作空间．本文将耦合型3-SRR/SRU 3自由度并联机构用于舰载稳定平台五轴联动补偿,拓展了少自由度并联机构的应用领域．     

六自由度并联机器人的支链选取

提出了六自由度并联机器人的支链选取的系统方法． 并联机器人中有多种类型的支链可以用来实现末端执行器的6自由度运动， 每个支链的驱动关节应当在基座上或靠近基座的地方， 由支链所构成的整个并联机构的自由度应当为6．利用这些条件对并联机器人的支链形式进行筛选可以获得可行的支链形式． 通过这种方法可以去除很多不可行的支链形式, 得到可行的支链形式供后续设计使用．     

Design of reactionless 3-DOF and 6-DOF parallel manipulators using parallelepiped mechanisms

In this paper, the design of reactionless 3-degree-of-freedom (DOF) and 6-DOF parallel manipulators is presented. At first, the design and dynamic balancing of a novel 3-DOF parallel mechanism referred to as the parallelepiped mechanism are addressed. Two types of actuation schemes of the mechanism are considered, and the two corresponding mechanical structures are designed. The balancing equations are derived by imposing that the center of mass of the mechanism is fixed and that the total angular momentum is constant with respect to a fixed point. Optimization is performed to determine the counterweights and counter-rotations based on the balancing conditions. Numerical examples of reactionless 3-DOF parallelepiped mechanisms are given. The dynamic simulation software ADAMS is used to simulate the motion of the mechanisms and to verify that the mechanisms are reactionless at all times and for arbitrary trajectories. Finally, the 3-DOF parallelepiped mechanisms are used as legs to synthesize reactionless 6-DOF parallel manipulators.     

5自由度并联机器人设计方法

本论文以螺旋理论为基础,提出一种系统的结构综合方法.根据各条支链对运动平台所提供的反螺旋 约束的线性关系,研究了构成五自由度并联机器人机构的各条支链所有可能的运动副组合以及它们的空间几何条 件.利用这一方法,设计出一组结构对称的五自由度并联机器人.     

基于螺旋理论的新型三自由度移动并联机器人奇异性分析

采用螺旋理论及线性几何学方法对具有3支链5关节（P-4R）的三自由度纯移动并联机器人的奇异性进行了分析和总结．研究了该并联机器人的结构奇异性以及主动关节（驱动关节）的配置的奇异性,并采用线性几何学图解形式直观地给出其处于奇异时的形位,为进一步研究其动力学、运动学性质奠定了基础．     

In-parallel actuated mechanisms as a new robotic mechanism

The concept of parallel connection or in-parallel actuation is described for the closed-loop mechanisms with multiple degrees of freedom which compose those manipulators or robots called parallel. The structural, kinematic, static and dynamic characteristics of the mechanisms are also explained. Then, possible applications of the mechanisms to robots as an alternative to conventional serial robots are introduced together with problems to be solved.     

Conceptual design and analysis of the 2T1R mechanism for a cooking robot

This paper deals with the design and analysis of a two-translation and one-rotation (2T1R) mechanism for a novel cooking robot. Firstly the motions involved in stir-fry, the most representative operation in the cooking processes used in Chinese cuisine, are analyzed in details. Then the featured motions are decomposed into four main movements that are used as a design base for a wok motion mechanism. Several three-degrees-of-freedom (DOF) parallel manipulators are considered. From these, a 2T1R mechanism is selected as an ideal candidate. A 4-DOF (2T1R+1T) cooking robot is constructed by combining the 2T1R parallel manipulator with a 1-DOF linear feed mechanism. It is shown that the combined 4-DOF robot can perform the required cooking operations, particularly the stir-fry. The analysis conducted on the proposed 2T1R parallel manipulator includes inverse kinematics, forward kinematics, the velocity analysis, the constant orientation workspace, and the total orientation workspace. A prototype of the cooking robot is developed. The experiments verify that the proposed cooking robot is suitable for performing the required operations.     

A Geometric Theory for Analysis and Synthesis of Sub-6 DoF Parallel Manipulators

Mechanism synthesis is mostly dependent on the designer's experience and intuition and is difficult to automate. This paper aims to develop a rigorous and precise geometric theory for analysis and synthesis of sub-6 DoF (or lower mobility) parallel manipulators. Using Lie subgroups and submanifolds of the special Euclidean group SE(3), we first develop a unified framework for modelling commonly used primitive joints and task spaces. We provide a mathematically rigorous definition of the notion of motion type using conjugacy classes. Then, we introduce a new structure for subchains of parallel manipulators using the product of two subgroups of SE(3) and discuss its realization in terms of the primitive joints. We propose the notion of quotient manipulators that substantially enriches the topologies of serial manipulators. Finally, we present a general procedure for specifying the subchain structures given the desired motion type of a parallel manipulator. The parallel mechanism synthesis problem is thus solved using the realization techniques developed for serial manipulators. Generality of the theory is demonstrated by systematically generating a large class of feasible topologies for (parallel or serial) mechanisms with a desired motion type of either a Lie subgroup or a submanifold.     

面向非完全姿态约束问题的旋转矩阵群中的垂线理论

在很多机器人领域,有很多给定任务要求并不需要3维空间的完整姿态约束,而是只限定了目标姿态某一轴的方向．这类问题称为非完全姿态约束问题．针对该问题,定义了旋转矩阵群中测地线的垂足和垂线,并给出了其解析表达式．基于垂线理论,提出了沿垂线规划的点到点轨迹生成算法．最后通过仿真实验求解操作臂的轨迹规划问题,仿真以6自由度的PUMA 560为平台,并依次固定第6关节、第4关节得到5自由度和4自由度的操作臂．提出的算法不仅适用于具有功能冗余的6自由度操作臂,也可应用于不具有冗余特性的5自由度和4自由度操作臂．实验结果验证了提出的理论和算法在解决非完全姿态约束问题上的通用性．同时,该算法还能避免参数表示方法中的奇异性问题．     

Adaptive neural network control of tendon-driven mechanisms with elastic tendons

We propose an adaptive control and an adaptive neural network control (composed of two RBF neural components and one adaptive component) for tendon-driven robotic mechanisms with elastic tendons. These controllers can be applied to serial or parallel tendon-driven manipulators having linear or non-linear elastic tendons. We begin by proving the stability of the adaptive control system for our mechanism, and then we prove the stability of the adaptive neural network system and report on the results of numerical simulations and experimental results performed using a 2-DOF tendon-driven mechanism having six elastic tendons.