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针对并联机器人在基于给定工作任务进行轨迹规划过程中,存在因机构误差引起的期望轨迹与理想轨迹之间的偏差,由此造成并联机器人运动学精度降低的问题,提出了一种并联机器人运动学精度提高新方法。首先将连续工作任务离散化为满足精度要求的若干理想位姿点,在建立并联机器人位姿误差模型基础上,将机构误差项转化为驱动杆误差;基于种群排列熵模型和粒子速度激活机制改进了粒子群算法,并利用改进的粒子群算法组合优化驱动杆参数,补偿并联机器人位姿误差,进而修正期望轨迹以提高并联机器人运动学精度。通过MATLAB和ADAMS仿真验证了所提出方法的可行性和有效性。 相似文献
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《制造业自动化》2021,(8)
三平移并联机器人内置传感器偏离并联中心,实际反馈机器人姿态信息不及时,导致分析得到的机器人运动姿态外倾角较小,针对该问题,优化设计三平移并联机器人的结构并构建运动学多目标分析过程。重构三平移并联机器人传动支路,调节传感器放置位置,设定机器人仿真参数,简化处理为运动指标,构建结构动力学方程,几何描述三平移并联机器人运动姿态,形成多目标分析算法。搭建机器人实验平台,应用基于时空差异的运动学多目标分析方法、基于柔性动力学的多目标分析方法与所设计的多目标分析方法进行实验,结果可知:所设计的运动学多目标分析方法得到的机器人运动姿态外倾角最大,且符合机器人的运动实际。 相似文献
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3自由度并联机器人的运动学与动力学分析 总被引:12,自引:1,他引:12
对一种空间 3 自由度并联机器人(3-RRS 并联机器人)进行运动学和动力学分析.此并联机器人的机构由一个动平台和一个静平台通过3个同样的转动副一转动副一球面副的支链组成.完全描述此并联机器人动平台的位置和姿态需要6个变量,即平台上一参考点的3个位移和3个转角.由于此并联机器人拥有2个转动自由度和1个移动自由度,所以,在动平台的6个位姿变量中只有3个变量是独立的.首先,推导此种并联机器人动平台的6个位姿参数之间的约束关系,给出这些变量之间的解析表达式.然后,基于Lagrange方程建立此并联机器人的动力学模型.在此基础上,通过算例分析驱动构件角速度、驱动力/力矩和能耗的变化规律.这些内容为进一步研究此种空间并联机器人的动态性能、机构优化设计和系统控制等都有非常重要的意义. 相似文献
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6R机器人正运动学分析是指给定各关节的关节空间变量值,求解末端执行器在工作空间的位置和姿态。利用6R弧焊专用机器人的机械本体结构,在D-H坐标系和旋量理论坐标系下建立了末端执行器的运动学方程,利用MATLAB软件求解位姿矩阵;在虚拟样机软件中建立了机器人运动学模型,进行运动学仿真得到末端执行器不同状态下的位移曲线。并将三种方法所得末端执行器的位姿进行了比较,验证了这三种方法的正确性。研究结果为后续的动力学分析、轨迹规划奠定了基础。 相似文献
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Generation and Simulation of Robot Trajectories in a Virtual CAD-Based Off-Line Programming Environment 总被引:2,自引:0,他引:2
This paper presents a new approach to the generation and optimisation of the position and orientation trajectories in Cartesian
task space, and simulation in a virtual CAD-based off-line programming environment. A novel concept of the robot pose ruled
surface is proposed, and defined as a motion locus of the robot orientation vector, i.e. the vector of equivalent angular
displacement. The planning for trajectories of robot end-effectors can be accomplished by generating the robot pose ruled
surface and optimising its area under the constraints with good kinematics and dynamics performances. The established optimisation
model is based on functional analysis and dynamics planning, and is simplified by using high-order polynomial space curves
as the robotic position and orientation trajectories. The developed system, RoboSim, is a virtual integrated environment which
can be used as a testbed for automatic motion planning and simulation for robots. Two examples are given to verify the feasibility
of the proposed approach and models, and to demonstrate the capabilities of generation, optimisation, and simulation modules
and libraries in the RoboSim package. The simulation results show that the approach and system are feasible and useful for
motion planning, performance analysis and evaluation, and CAD-based prototyping and off-line programming in both the virtual
and the real design and planning environment. 相似文献
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X. F. Zha X. Q. Chen 《The International Journal of Advanced Manufacturing Technology》2004,23(11-12):831-845
Motion coordination planning and control play a crucial role in robot application to Cartesian task operations with taking into account kinematics and dynamics constraints. This paper presents a unified approach to coordination planning and control for robot position and orientation trajectories in Cartesian space. The concept of generalised robot pose is defined as the robot configuration consisting of position and orientation, in which the orientation is described by a vector equivalent to the rotational angular displacement. The robot pose ruled surface is formed as a three-dimensional motion locus of its configuration vector. The unified treatment of the end-effector positions and orientations is based on the robot pose ruled surface concept and used in trajectory interpolations. The coordination planning of pose trajectories for the robot end effector is accomplished by generating and optimising the pose ruled surface under the constraints of kinematics and dynamics performances. The coordination control is implemented through controlling the motion laws of two end points of the orientation vector and calculating the coordinates of instantaneous corresponding points. The simulation experiment using PUMA 560 robot in arc welding and surface finishing processes are carried out to verify the feasibility of the proposed approach and demonstrate the capabilities of generation and control models. 相似文献
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Juan Carlos JáUREGUI Eusebio E. HERNáNDEZ Marco CECCARELLI Carlos LóPEZ-CAJúN Alejandro GARCíA 《Frontiers of Mechanical Engineering》2013,8(3):252
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. 相似文献
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研究了一类1T2R并联机构拓扑结构综合和优选。应用平面机构的组成原理和约束特性,将1T2R并联机构拓扑结构视为由一条串接一转动副的1T1R平面并联运动链和两条空间无约束主动支链组成。统筹考虑机构位姿能力恰当性、支链结构力学合理性、机器人模块可重构性、位置逆解简易性和动平台结构紧凑性等准则,完成1T2R并联机构拓扑结构优选及性能验证。在此基础上,提出一种可继承Tricept机器人优点的新型五自由度混联机器人模块,该模块具有与Tricept机器人完全相同的运动学性能,且绝大部分部件可与Tricept机器人互换。 相似文献
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为满足医疗上的任务灵活空间的要求,提出了一种新型的机器人机构,并从定义上考证,确定为单闭链并联机器人构型.文中用螺旋理论的矢量形式表示了运动输出特征方程,根据机器人机构拓扑结构理论分析了机构的活动度,同时通过公式对任务灵活空间进行了分析,绘制了动平台空间姿态随参数变化的规律表,提出了影响并联机构任务灵活空间的关键参数.对并联机器人构型的设计提供了一种理论上的参考. 相似文献
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Error Modeling and Sensitivity Analysis of a Parallel Robot with SCARA(Selective Compliance Assembly Robot Arm) Motions 总被引:2,自引:1,他引:1
Parallel robots with SCARA(selective compliance assembly robot arm) motions are utilized widely in the field of high speed pick-and-place manipulation. Error modeling for these robots generally simplifies the parallelogram structures included by the robots as a link. As the established error model fails to reflect the error feature of the parallelogram structures, the effect of accuracy design and kinematic calibration based on the error model come to be undermined. An error modeling methodology is proposed to establish an error model of parallel robots with parallelogram structures. The error model can embody the geometric errors of all joints, including the joints of parallelogram structures. Thus it can contain more exhaustively the factors that reduce the accuracy of the robot. Based on the error model and some sensitivity indices defined in the sense of statistics, sensitivity analysis is carried out. Accordingly, some atlases are depicted to express each geometric error’s influence on the moving platform’s pose errors. From these atlases, the geometric errors that have greater impact on the accuracy of the moving platform are identified, and some sensitive areas where the pose errors of the moving platform are extremely sensitive to the geometric errors are also figured out. By taking into account the error factors which are generally neglected in all existing modeling methods, the proposed modeling method can thoroughly disclose the process of error transmission and enhance the efficacy of accuracy design and calibration. 相似文献
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变胞多指灵巧手分析 总被引:1,自引:0,他引:1
对戴建生提出的新型的变胞多指灵巧手进行分析。该灵巧手与目前常用的机器手最大的不同在于它的手掌可以活动,并具有变胞功能。手掌的变胞增强了机器手的灵巧度并增大了工作空间。当手掌杆件静止的时候,每个手指都在一个平面内运动,由此提出手指操作平面的概念,从而将研究抓取姿态的问题转化为研究手指操作平面单位法矢量的问题。建立球面变胞手掌的全局坐标系,并得到3个手指平面的单位法矢量在此全局坐标系下的表示,然后将抓取姿态映射成为姿态直纹面。将机器手的工作空间分为手指和手掌两部分,着重研究后者,提出工作空间三角形的概念。工作空间三角形随着手掌的运动而变化,映射成为手掌工作空间直纹面后可以直观地了解其形状和大小的变化情况。 相似文献
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柔索并联机构是一类新型的机构 ,具有一些优于其他机构的特点 ,但因柔索特性的限制 ,可实现的运动形式较少。本文通过增加约束机构对运动平台运动进行限制 ,扩大了柔索并联机构的应用范围。文章提出约束机构的概念 ,讨论了约束机构的种类 ,并进行奇异位形的分析。 相似文献