六自由度微动平台机构设计.doc

摘 要 本文对一种新型的6-(P-2P-S)并联机器人的进行了分析Stewart平台经过变异得到介绍了该的特点，利用空间机构学理论分析了机构的位置正反解，并分析了该机构在正交位姿的运动解耦性能。 基于该的结构约束，研究了该机构的工作空间，并定量分析了该机构参数对工作空间体积大小的影响。 定义了线速度各向同性性能评价指标，并给出各向同性性能指标在工作空间内的分布情况。采用对并联机构运动学方程取微分的方法求得各和末端误差的映射关系，使用叠加原理获得了在综合多种误差影响因素作用下并联机构的几何误差，利用蒙特卡洛技术对终端平台误差进行了分析。采用绝对误差敏感度和误差方向敏感度这两个误差评价指标，将误差影响因素对机构终端误差的影响进行了分析。 以该并联机构的全域各向同性性能指标和全域综合误差指标为依据对该机构进行了参数设计。 关键词 并联机器人；正交结构；性能指标；误差；蒙特卡洛方法Abstract The thesis focuses on the accuracy research on a novel 6-(P-2P-S) orthogonal parallel robot, the robot is developed based on the Stewart platform mechanism. Its layout feature is presented according to the previous research results. The forward and reverse position are established by using spatial mechanisms. The paper also shows that the novel parallel robot is characterized by decoupling at its orthogonal position. Base on the architecture constraints, its workspace is investigated. The effects of the design parameters to the workspace volume are studied quantitatively. Kinematics transmission isotropy evaluation criteria is defined. The distribution of the defined evaluation criteria are presented on the workspace. To get the mapping relationship between the influencing factors and the end error of the 6-(P-2P-S) parallel robot, the kinematics equation are differentiated. The analytic expression of the geometric error of the 6-(P-2P-S) parallel robot is obtained by using the superposition theorem and comprehensively considering the influencing factor. The distribution on terminal platform errors is discussed using Monte-Carlo method. By comprehensively considering the two evaluation indicators: absolute error sensitivity and error isotropy sensitivity, the influence of the influencing factor effecting on the end effector is analyzed. Based on the workspace of a novel 6-(P-2P-S) parallel robot, geometry parameter of the parallel mechanism is optimized which depend on the glob kinematics and the glob equal errors. Keywords Parallel robot; Orthogonal structure; Performan