三平移并联机构3-RRC的工作空间分析

机器人的工作空间是衡量机器人性能的重要指标之一。并联机器人的工作空间决定着并联机器人的整体尺寸。通过矢量法建立了三平移并联机器人机构3—RRC的位置正反解方程，探讨了结构参数对该并联机构工作空间的影响规律，为扩大工作空间提供了途径，且为工作空间的综合提供了依据。该并联机器人机构在工业装配机器人、力与力矩传感器、虚拟轴机床、坐标测量机等领域具有广泛的应用前景。     

一种新型3自由度并联机构的奇异性分析

研究一种新型空间3自由度并联机构(HANA)的奇异性。该机构由定平台、动平台和三个联接支链组成，其动平台相对于定平台具有2个移动和1个转动自由度。其结构主要特点是只采用了单自由度的运动副。构型优势主要是转动自由度灵活度高。详细分析了该机构的三类奇异形位，为以后关于该机构的工作空间和转动能力分析以及控制提供基础，特别是基于合理设计的工作空间内无奇异特性将保证该机构拥有很高的转动能力。该机构不仅可以应用在并联机床的设计中，还可以广泛地应用在工业机器人、飞行模拟器和微型机器人等领域。     

Position,Singularity and Workspace Analysis of 3-PSR-O Spatial Parallel Manipulator

Although the parallel mechanisms have the advantages of high accuracy, velocity, stiffness, and payload capacity, the shortcomings of the space utilization and workspace limit the applications in the c...     

一种3T1R并联机构设计及运动学性能分析

设计了一种能实现三维移动和一维转动的4自由度并联机构。分析了机构的拓扑结构及自由度特征。建立了机构位置正反解数学模型,并采用二维搜索法进行数值验证。分析了机构的工作空间、雅可比矩阵以及机构的奇异位形特征。设计了SPS和RRR两种冗余驱动支链,结果表明RRR冗余支链可在保持机构工作空间不变的前提下,有效消除机构的内部正解奇异。     

Singularity analysis with respect to the workspace of a double parallel manipulator

Singularity analysis is an important issue in the design of parallel manipulators, since they become uncontrollable at singular configurations due to the rank deficiency of the Jacobian. This paper analyzes the singularity of a double parallel manipulator with respect to its workspace. The workspace is decoupled into a positional workspace generated by the first parallel mechanism, and an orientational workspace by the second mechanism. The singularities occurring outside each workspace are analytically found by a Jacobian matrix derived for the velocity transformation from the end-effecfor to the linear actuators. The singularity loci are presented and their geometric properties are examined to prove that the double parallel manipulator is free from the singularity problem.     

Parameter Optimization of a Stability-Training Platform's 4-PSS/PS Parallel Mechanism Based on Training Ability Evaluation Index and PSO Algorithm

The existing mechanism parameter optimization(MPO) method of parallel mechanisms only considers the workspace size and ignores contribution of each configuration's performance. So a novel MPO method is proposed for our serial?parallel mechanism platform,which is used in stability training of legged robots. Regarding the platform's parallel mechanism part,a 4?PSS/PS parallel mechanism,two object functions and three constraint conditions are defined to establish the MPO model. The first object function uses critical motion indexes of the moving platform. The second one uses derivative function of the defined disturbance Lagrange function. After analyzing stability?training require?ments of five existing legged robots,requirements of the platform's motion capability are given out. Regarding each proposed object function separately,the MPO model is solved by the particle swarm optimization(PSO) algorithm. Valid workspace boundaries corresponding to the optimization results are solved by a numerical method. The overall optimal solution is determined based on volume of the valid workspace. It is revealed that the two object functions result in similar optimization solutions,which shows that the proposed object functions can reflect the stability?training ability consistently. This paper proposes and verifies the established MPO model,which considers both the workspace size and configurations' performance evaluation.     

Dimensional Synthesis of a 3-DOF Parallel Manipulator with Full Circle Rotation

Parallel robots are widely used in the academic and industrial fields. In spite of the numerous achievements in the design and dimensional synthesis of the low-mobility parallel robots, few research ef...     

基于2TIR机构串并联机器人位置分析及仿真

根据串联机构和并联机构的特点,设计了一种串并联机器人新机型。通过对该机器人机构运动特征分析,求出了其位置正反解析解,并将用PRO/E建立的虚拟样机导入到ADAMS软件中进行了位置的动态仿真,验证了理论分析的正确性。该机器人动平台具有三个平移和一个转动自由度,与具有同样运动特性的并联机构相比,该机器人机构的工作空间大,转动自由度运转灵活。同时,该机器人机构的运动学正反解求解容易,便于实现实时控制。该机器人机构可应用于工业机器人、中医推拿机器人等领域。     

2自由度高速高精度并联机器人的运动学优化设计

提出一种基于工作空间综合和灵巧度、速度和几何精度等性能指标分析的2自由度并联机器人运动学优化设计方法,构造一种由灵巧度、运动速度和运动分辨率等变量组合而成的工作空间全局评价指标。优化过程分为两步进行：首先以灵巧度、力传递特性和避免奇异位形的几何条件为约束,综合出具有良好特性的工作空间,在此基础上研究不同杆长比下实现目标工作空间所需的尺度参数;然后根据全局运动学性能评价指标从第一步的优化结果中遴选出最合适的杆长比,从而实现了对机构的几何尺度参数优化。并给出了算例以说明方法的有效性。     

Design procedure for cuspidal parallel manipulators

In the design of parallel manipulators, a major problem is their reduced operational workspace. This is mainly due to the existence of a complex singularity locus within the workspace. The singularity-free workspace therefore corresponds to only a fraction of the potential workspace, and dimensioning the manipulator is intended to optimize such singularity-free workspace. The singularity locus often divides the workspace into isolated volumes according to assembly modes and working modes. As a result, it is common to restrict the operational space to a simple geometric shape inside a singularity-free workspace. However, it is well known that appropriate motion planning can make the most of a more complex workspace by means of transitions between working mode and/or assembly mode. In this paper, the authors obtain the locus of cusp points in the joint space entity, which will permit non-singular assembly mode changing in cuspidal manipulators. Making use of such entity, the optimum dimensional parameters are obtained which increase the possibility of non-singular transitions while obtaining a maximal, regular-shaped workspace.     

Analysis and simulation for a parallel drill point grinder

To meet the quality and flexibility requirements of a hole-making process and to overcome the limitations of traditional manual grinding and cam-type automatic grinding in new drill point geometry development, a three degrees of freedom (3-DOF) parallel-mechanism-based drill point grinder is proposed in this paper. With the consideration of different inclination angle configurations of the grinder guideway, the inverse kinematics and the workspace analysis of the parallel grinder are developed; the relationship between the workspace and the structural parameters of the grinder, such as installation pattern, radius of joint distribution circle, length of the links etc. is discussed in detail. A numerical–symbolic method and a net search method are employed in the singularity analysis. The analysis of the kinematics, workspace and singularity provides the basis for understanding the characteristics of the new parallel grinder and also helps in the structural design of the proposed grinder.     

“被动冗余度”空间机器人运动学特性分析

分析了“被动冗余度”空间机器人主、被动关节之间的运动学耦合,得到了可用于运动学规划的耦合指标;分析了“被动冗余度”空间机器人的运动学奇异的问题,以及与对应全主动关节冗余度空间机器人的运动学奇异的区别,得到的新的可操作性指标同样可用于机器人的运动规划;推导出了“被动冗余度”空间机器人的最佳最小二乘运动学优化方程,通过“准自运动”实现被动冗余度空间机器人优化控制;通过对平面3自由度空间站机器人的仿真,证实了分析得到的结论。     

一种无汇交轴线对称三转动并联机构的运动分析

传统的三自由度转动并联机构（又称球面并联机构）一般都有一个转动中心,且这个中心点往往是分支间多个运动副轴线的汇交点,这种严格的几何条件给机构的加工制造带来很大的难度,制约了这类机构的应用。针对此,提出了一种无汇交轴线的对称三转动并联机构,其三个分支对称布置,分支内及分支间均无汇交轴线。对机构进行了位置反解,得到了机构四种对称的装配构型;从分支运动奇异、平台约束奇异和驱动奇异三个方面对机构进行了奇异分析;最后给定了一组尺寸参数,采用数值搜索的方法得到了机构的姿态工作空间。通过结果可以看出,该机构可以实现三维转动,具有较大的姿态工作空间,而且制造装配相对容易,具有很好的应用前景。     

Design and analysis of partially decoupled translational parallel mechanisms with single-loop structures

This study presents a family of novel translational parallel mechanisms (TPMs) with single-loop topological structures. The proposed mechanism consists of only revolute and prismatic joints. The novel TPMs are simpler in structure and have fewer joints and components than the well-known Delta Robot. Four types of 2-degree of freedom driving systems are applied to different limb structures to avoid the moving actuator that causes the problem of increased moving mass. Four sample TPMs are constructed using the synthesized limbs, and one of them is investigated in terms of kinematic performance. First, a position analysis is performed and validated through numerical simulation to reveal the characteristics of partially decoupled motion, which improves the controllability of TPM. Second, singular configurations are identified, and the resulting singularity curve is obtained. Lastly, the workspace of TPM is analyzed, and the relationship between the singular configurations and the reachable workspace is explored. The workspace of the 3-CRR (C denotes the cylindrical joint and R denotes the revolute joint) translational mechanism is also presented to prove that the proposed TPM has a fairly large workspace.     

三自由度冗余驱动并联机构的奇异性和工作空间分析

基于4-SPS/S三自由度冗余驱动并联机构的位置逆解模型,运用微分法推导出了该并联机构的雅可比矩阵,结合Gosselin奇异性分析法和数值分析法,分析了该并联机构的奇异性。随后分析了影响4-SPS/S三自由度冗余驱动并联机构工作空间的主要因素,并对其各支链的行程限制、各球铰副的转角限制和各支链间的尺寸干涉限制等影响因素进行了解析化分析。最后,基于4-SPS/S三自由度冗余驱动并联机构的位置正解模型,设计了该并联机构回转工作空间的求解算法。该算法避免了数值方法及几何方法的复杂性和不确定性,实现了回转工作空间的直观性表达。     

新型6-PRRS并联机器人工作空间与结构参数研究

针对一种新构型的6-PRRS并联机器人,研究了该机构中长杆、短杆、固定平台、动平台结构参数的变化对其工作空间的影响.根据此类并联机器人工作空间形状的特点,提出一种比较简便的工作空间大小比较方法.不同的结构参数对应于不同的工作空间,通过机构参数影响的分析,为此类并联机器人的应用与设计提供直接的依据.     

考虑工作空间与力传递效率的新型五自由度混联机器人设计与分析

提出了一款构型为R(2RPR)R/SP+RR的新型五自由度混联机器人,对其性能进行分析,并依据工作空间与力传递效率性能指标进行尺寸优化,获得了关键设计尺寸;在此基础上,进行混联机器人本体结构设计与刚度分析,并与其他同类典型机器人刚度进行了对比;最后分析了混联机器人工作空间,提出一种工作空间搜索方法,分析了机器人在不同布局情况下工作空间是否满足预期。     

合作机器人的被动约束特性及实验研究

合作机器人(Cobot)是在同一作业空间与人直接物理合作的机器人。为了实现Cobot与人直接合作,Cobot的关节机构必须具有被动约束特性。建立了一种基于双超越离合器的不完全约束关节机构的模型和它的控制模型,对关节机构的被动约束特性和Cobot的轨迹跟踪特性进行了实验研究。实验结果表明,不完全约束关节机构具有被动特性,并能约束Cobot关节的运动状态,并能使Cobot在不同操作力作用下跟踪期望轨迹,不会因机器人失控伤害操作者,满足Cobot与人合作的要求。具有这种关节机构的Cobot可以应用在外科手术、物料搬运和零件的装配等需要人机合作的场合。     

关节型工业机器人工作空间及结构尺寸参数的一种确定方法

提出了一种适用于工程设计的确定关节型工业机器人工作空间及结构尺寸参数的简易而又实用的方法。根据机器人工作空间主视图边界曲线上特定的三点座标值，利用数值计算方法就可以确定机器人的结构尺寸参数（大小臂长度Ｌ１和Ｌ２的值，及其旋转角θ１和θ２的极限值），再根据这些结构尺寸参数确定机器人的工作空间。另外依此编制了相应的软件Ｒｏｂｓｐａｃｅ，只要输入三点的座标值及机器人机座的高度和机座旋转角度，便能确定机器人结构尺寸参数及其工作空间，并能显示、打印结构尺寸参数结果及工作空间边界曲线。     

绳牵引并联机构的研究概况与发展趋势

总结了近20年来关于绳牵引并联机构的研究概况和研究内容；论述了绳牵引并联机构的构型、工作空间、刚度和冗余性等方面的研究；分析了绳牵引并联机构的应用前景与发展趋势，指出了绳牵引并联机构在建筑机器人、虚拟现实的力反馈装置和触觉装置、大型运动仿真器、大型射电望远镜、超高速机器人、超大工作空间的轻型机器人和风洞试验等领域的应用前景，展望了绳牵引并联机构的预期研究内容。