Kinematics and optimization of 2-DOF parallel manipulator with revolute actuators and a passive leg

In this paper, a 2-DOF planar parallel manipulator with two revolute actuators and one passive constraining leg. The kinematic analysis of the mechanism is analytically performed: the inverse and forward kinematics problems are solved in closed forms, the workspace is derived systematically, and the three kinds of singular configurations are found. The optimal design to determine the geometric parameters and the operating limits of the actuated legs is performed considering the kinematic manipulability and workspace size. These results of the paper show the effectiveness of the presented manipulator.     

基于Pro/E和ADAMS的欠驱动苹果采摘机械手运动学仿真分析

将欠驱动技术应用于农业采摘领域,欠驱动手指作为水果采摘机器人的末端执行器.对手爪的抓取力进行了分析,利用Pro/E完成对苹果采摘机械手的虚拟设计与装配;利用ADAMS对机械手进行运动学、动力学仿真,获得其速度、加速度和接触力的变化情况曲线,仿真结果表明,机械手的设计符合要求,并为实现机械手的控制提供了重要依据.     

Dynamics analysis of novel parallel manipulator with one central rotational actuator and four translational actuators

A dynamics analysis of a novel parallel manipulator with one central rotational actuator and four translational actuators is conducted. A 3D model of the parallel manipulator is constructed and its characteristics and DoF are analyzed. The kinematics formulae are derived for solving the displacement, velocity and acceleration of the moving links. The dynamics formulae are derived for solving the inertial wrench of the moving links, the dynamic active forces along the active limbs, the dynamic active torque applied on a central active leg, and the dynamic constrained force exerted on the central active leg. A theoretical numerical example is given to solve the kinematics and dynamics solutions, and the theoretical solutions are verified by the simulation mechanism in Matlab. Finally, a reachable workspace of the novel parallel manipulator is constructed using CAD variation geometry.

     

7自由度冗余绳驱动机械臂运动分析及仿真

针对传统机械臂负载自重比小、臂身惯量大、人机交互安全性弱等问题,对绳驱动机械臂的结构、绳驱关节耦合、冗余运动学等方面进行了研究,创新设计了一种新型7自由度冗余绳驱动机械臂。采用绳索间接驱动前端4个关节自由度,作为位置控制;采用电机直接驱动腕部关节3个自由度,作为姿态控制。利用绳索将驱动力从基座电机传递至机械臂关节处,实现驱动机构后置;对绳驱关节耦合问题进行分析,建立了电机-关节耦合映射关系;利用位姿分离方式,结合加权最小范数法,进行机械臂逆运动学冗余位置求解。仿真结果表明:耦合映射关系建立正确,冗余运动学求解准确高效,为绳驱机械臂结构优化、动力学建模奠定了基础。     

气动人工肌肉并联机器人平台

提出一种基于气动人工肌肉的新型3自由度并联机器人平台,该机器人平台结构简单,具有3转动自由度。在对该新型3自由度并联机器人平台运动学和动力学特性理论分析的基础上,采用模糊变结构控制策略设计了新型3自由度并联机器人平台的两层滑模模糊变结构控制器,并建立了试验系统,开展了新型3自由度并联机器人平台的试验研究,其最大位置跟踪误差0．3 mm,当气源压力改变后,最大跟踪误差仍小于0．6 mm。试验结果表明,采用气动人工肌肉作为驱动装置设计的3自由度并联机器人平台是可行的,两层滑模模糊变结构控制策略对于该系统是适合的。     

Three-degree-of-freedom Parallel Manipulator to Track the Sun for Concentrated Solar Power Systems

In concentrated solar power(CSP) generating stations, incident solar energy is reflected from a large number of mirrors or heliostats to a faraway receiver. In typical CSP installations, the mirror nee...     

Kinematics analysis and numerical simulation of a manipulator based on virtual prototyping

Manipulator kinematics refers the analytical study of the motion of manipulator, such as positions, velocities, and accelerations of the links of a manipulator. As formulating the suitable kinematics models for a manipulator is very crucial for analyzing the behavior of manipulators and light weight design of manipulators, many researches have been focused on it in recent decades with a result of many valuable contributions. However, current researches always focus on rigid manipulator, while the manipulator is always a rigid-flexible coupling multibody system, which can affect the accuracy of kinematics analysis and numerical simulation. This paper proposed a model of kinematics analysis of manipulator based on rigid-flexible coupling virtual prototyping. After a model of manipulator kinematics based on the D-H method was proposed, rigid-flexible coupling virtual prototyping-based kinematics simulation and numerical simulation was then put forward. The kinematical experiment is carried out based on manipulator physical prototyping, which demonstrates that the accuracy of the kinematics calculation and the rationality of design based on rigid-flexible coupling virtual prototyping. The design of a five-degrees-of-freedom manipulator is given as an example, which demonstrates that the methodology is obviously helpful to manipulator design.     

高压特种作业机械手运动学分析及仿真

高压输电线路长时间暴露在外,会产生输电线路故障,需及时发现并维修。为此,设计了高压输电线路维修机械手,并对其运动学进行了分析。设计的机械手自由度为6个,且6个关节均为旋转关节。首先确定机械手的连杆坐标,连杆的D-H参数,使用Matlab来绘制机械手三维模型。运用Robotics Toolbox中的FKINE和IKINE两个函数来求解机械手的运动学的正解问题和逆解问题。     

一种新型四自由度并联平台机构及其位置分析

提出了一种能实现空间三维移动和绕 z轴转动的并联机器人机构模型——空间4- TRT并联机构。文中采用螺旋理论分析了它能实现空间三维移动和绕 z轴转动的机构学原理 ,计算了它的自由度 ;给出了其位置反解的方法 ,推导出了位置正解的封闭方程 ,并进行了数值验证。     

四滑块平台机构及其运动学建模

提出一种用水平导轨上4个滑块作为原动件的混合型4自由度并联平台机构，该机构的动平台能够实现2个方向的移动以及绕2个方面轴线的转运，研究了该机构的运动学建模方法，给出了运动学正逆解，并阐述了春应用前景。     

Kinematics of a star-triangle planar parallel manipulator

This paper addresses kinematics of a 3 degree-of-freedom (DOF) planar parallel manipulator called Star-Triangle manipulator. The manipulator has good accuracy and a relatively large singularity-free workspace. First, position analysis of the manipulator is implemented indicating that both the inverse and forward position problems of the manipulator have only one solution. Then, velocity and singularity analyses of the manipulator are carried out and its isotropic configurations are identified using two Jacobian matrices. Based on the isotropic conditions, the workspace of manipulator is determined geometrically and it is shown that all points in the workspace are free of singularities. At last, kinematic accuracy of the manipulator is investigated on the workspace through a kinematic conditioning index (KCI).     

Kinematic analysis and optimal design of 3-PPR planar parallel manipulator

This paper proposes a 3-PPR planar parallel manipulator, which consists of three active prismatic joints, three passive prismatic joints, and three passive rotational joints. The analysis of the kinematics and the optimal design of the manipulator are also discussed. The proposed manipulator has the advantages of the closed type of direct kinematics and a void-free workspace with a convex type of borderline. For the kinematic analysis of the proposed manipulator, the direct kinematics, the inverse kinematics, and the inverse Jacobian of the manipulator are derived. After the rotational limits and the workspaces of the manipulator are investigated, the workspace of the manipulator is simulated. In addition, for the optimal design of the manipulator, the performance indices of the manipulator are investigated, and then an optimal design procedure is carried out using Min-Max theory. Finally, one example using the optimal design is presented.     

基于MATLAB五自由度机械手运动学仿真分析

五自由度工业机械手可应用于搬运、码垛作业时对目标物体的抓取。以该五自由度工业机械手为研究对象,用常规的D—H法建立运动学数学模型,进行正、逆向运动学分析,然后,利用代数法依次求解出正、逆运动学方程,分别得出了操作臂末端在基坐标系下的位置关系式和各关节的参数变量,最后,用MATLAB软件对正运动学分析结果进行了仿真。     

一种新型水下作业机械手的研究

设计了一种可用于水下3000m作业的7自由度机械手；运用机器人运动学理论中的D—H参数法建立了机械手的运动学模型，并详细描述了该机械手的工作空间；然后用蒙特卡洛法并借助MATLAB对其工作空间进行了求解与仿真。     

平面结构冗余并联机构的误差敏感度分析

针对一种含闭环支链的平面结构冗余并联机构进行误差敏感度分析。分析了该机构的逆运动学和正运动学。基于矩阵法建立了机构的误差模型,并通过反解、正解结合的方法对该误差模型进行了验证。基于误差模型,得到了评价机构误差敏感度的指标,绘制了各指标在工作空间内的等值线图。基于误差敏感度指标,定义了低误差敏感性工作空间,绘制了低误差敏感性工作空间在工作空间中的分布图。与平面3-RRR并联机构进行了误差敏感度对比分析。结果表明,该机构的低误差敏感性工作空间占比较大,同时可以通过调节其冗余支链不断扩大低误差敏感性工作空间,使机构在大范围空间中保持低误差敏感性。     

Motion capability analysis of a quadruped robot as a parallel manipulator

This paper presents the forward and inverse displacement analysis of a quadruped robot MANA as a parallel manipulator in quadruple stance phase, which is used to obtain the workspace and control the motion of the body. The robot MANA designed on the basis of the structure of quadruped mammal is able to not only walk and turn in the uneven terrain, but also accomplish various manipulating tasks as a parallel manipulator in quadruple stance phase. The latter will be the focus of this paper, however. For this purpose, the leg kinematics is primarily analyzed, which lays the foundation on the gait planning in terms of locomotion and body kinematics analysis as a parallel manipulator. When all four feet of the robot contact on the ground, by assuming there is no slipping at the feet, each contacting point is treated as a passive spherical joint and the kinematic model of parallel manipulator is established. The method for choosing six non-redundant actuated joints for the parallel manipulator from all twelve optional joints is elaborated. The inverse and forward displacement analysis of the parallel manipulator is carried out using the method of coordinate transformation. Finally, based on the inverse and forward kinematic model, two issues on obtaining the reachable workspace of parallel manipulator and planning the motion of the body are implemented and verified by ADAMS simulation.     

混合型4自由度并联机构及其运动学建模

提出一种混合型４自由度并联平台机构，该机构的动平台能够实现两个方向的移动以及绕两个方向轴线的转动。研究了该机构的运动学建模方法，给出了运动学正、逆解。基于本文所提出的４自由度并联机构已成功地研制出一台五坐标并联机床。     

基于ADAMS的危险作业机械手工作轨迹分析

利用SolidWorks软件创建机械手的虚拟样机模型,采用D-H法对机械臂进行正向运动学分析和解算,为进一步验证解的正确性,运用ADAMS软件对机械臂运动特性进行仿真分析,得到了机械手处于2种抓取位姿时手爪形心随大臂俯仰的轨迹曲线,与经过正向运动学分析由Matlab绘制的曲线相吻合,这就证明了正向运动学分析的正确性。同时,基于ADAMS的机械手工作轨迹分析,为机械臂的优化设计及运动控制提供了参考依据。     

五自由度泄漏封堵移动机械臂运动学模型

泄漏对堵移动机械臂由移动平台和安装在平台上的机械臂组成,建立移动机械臂的运动学模型是设计泄漏封堵移动机械臂的理论基础.根据槽罐泄漏机械臂必须完成的动作,建立了五自由度泄漏封堵移动机械臂运动学模型,利用逆运动学的求解,进行了该模型的Matlab仿真,结果表明该运动学模型是可行的.     

新型6—PSS微操作机器人的静力分析基础研究

微操作机器人的静力分析对其结构设计和驱动的选择有重要意义。介绍了一种新型并联微操作机器人的结构布局特点,基于出的办输入输出关系矩阵的奇异分解,以其静力和力矩传递性能及其与结构几何参数的进行了分析。结果表明,该微操作机器人的静力和力矩传递性能可以分别用两个圆球直观表征,所以该微操作机器人的静力和力矩传递性能是各向同性的。