[PP]S类并联机构论文：[PP]S类并联机构伴随运动分析与构型设计

1、PPS 类并联机构论文：PPS 类并联机构伴随运动分析与 构型设计【中文摘要】空间少自由度并联机器人机构和传统的六自由度并 联机构相比，具有结构简单，设计制作和控制的成本都相对较低的特 点。作为少自由度并联机构的很重要的一种,S 类并联机构因其具有 两转一移的自由度，受到了广泛的关注，因而在工业上具有很大的应 用潜力。本文主要研究 S 类并联机构存在着的伴随运动问题，旨在揭 示 S 类并联机构中各项几何结构参数与伴随运动的内在联系，据此构建无伴随运动的 S 类并联机构新构型，并对其进行运动学分析及样机 的建立。主要内容包括以下几个方面：基于三个分支平面以及三个球 铰中心之间的相对位置关系，对

2、S 类并联机构分类，运用运动学方法，分别对其进行伴随运动的分析并作比较。 建立其各项几何结构参数与 伴随运动的内在联系，进而提出一般 3-PRS 并联机构无伴随运动所必 须满足的结构几何条件，该结论还适用于其他 S 类并联机构。基于无 伴随运动的结构条件，演出多种无伴随运动 S 类并联机构及其拓扑机 构。运用螺旋理论，对 3-PRRU 并联机构进行了自由度分析，并讨论其 消极运动副和伴随运动；利用无伴随运动 3-PRRU 机构的结构特点，简 化位置正反解，同时给出了刀具的位置方程。最后建立 3-PRRU 并联机 构的速度雅可比。基于速度雅可比，分析 3-PRRU 并联机构的各种奇异 位形以及驱

3、动失效。提出 3-PRRU 机构的摆动能力，利用摆动能力得出 机构刀具末端的工作空间，最后得到机构在不同姿态下的灵巧度。通 过考察灵巧度的性能图谱，了解机构在那些位姿的时候，运动性能最 差,从而使得机构在实际运动过程中，尽量避开这些位姿，提高机构运 行时的可靠性。本文研究工作对所有无伴随运动 S 类并联机构的研究具有重要的指导意义。【英文摘要】Compared with the gen eral 6-DOF (degrees offreedom) parallel mecha ni sm, lower-mobility parallel mecha ni sms haveadva ntages

4、 of simple structure, low cost in design, manufacturing andcontrol. The PPS parallel mecha nism (PM) is an importa nt category oflower-mobility parallel mecha ni sms and has received exte nsive atte ntion, which can undergo one translational degree of freedom (DOF) andtwo rotationalDOFs. Thus, the P

5、PS PMhas great potential inpractical applicati on. This paper focuses on the parasitic moti on of PPSparallel mecha ni sms and aims to reveal the in here nt link betwee n thegeometrical structural parameters with the parasitic moti on. Based on thestructural con diti on, the new PPS parallelmechanis

6、ms withoutparasitic motion canbe con structed. And the n kin ematic an alysis of 3-PRRU PM areproposed, the prototype is constructed. The main contributions are asfollows.Based on the relative positi on relati on ship betwee n three limbpla nes(LPs) and three cen ters of spherical hinges, the family

7、 of PPSparallel mechanism is classified.Then analyze its parasitic motion by using the kinematics methodrespectively and compare with each other.The in here nt link betwee n thegeometrical structural parameters and the parasitic motionisestablished, and the necessary structuralparameters for a gen e

8、ral 3-PRS parallel mecha nism without parasiticmoti on are proved. The sufficie nt and n ecessary structuralconditionis also applicable to other PPS parallelmechanisms. Based on the structural condition, evolve the multiple familyof PPS parallel mechanisms and its topological mecha ni sms.Thedegree

9、of freedom of a 3-PRRU parallel mecha nism is an alyzed byusing screw theory, and its in active pairs and parasitic moti on isdiscussed. Take adva ntage of structural character of a 3-PRRU parallelmecha nism without parasitic moti on, forward and inv erse positionanalysis is simplified, and the tool s positionformulation also be listed. Then build the velocity jacobi of the 3-PRRUparallel mecha ni sm.Based on velocity jacobi, analyze the multiplesingularities and actuation failure of 3-PRRU parallel mechanism. Andthen propose its capability of orientation whic