【作者】 覃艳明；

【导师】 张一同；

【作者基本信息】 燕山大学 ， 机械电子工程， 2003， 硕士

【摘要】 本文对一种新型五自由度并联立式数控机床的运动学、灵巧度、奇异位形、精度几个方面进行了比较全面和系统的分析。介绍了这种新型并联机床机构的组成及其特点，利用自由度公式和反螺旋两种方法计算了该机床机构的自由度。对中间约束支链和五驱动支链分别进行了运动学分析，并求出五驱动支链的反解。导出此并联机床的速度雅克比矩阵和力雅克比矩阵。通过分析雅克比矩阵的条件数来判断关节空间和目标空间的速度传递性和力传递性，利用Matlab工具软件进行具体计算，并画出性能的三维图形来使分析可视化。把性能优化作为判断灵活工作空间的一个判据，考察灵活工作空间边界的各向同性。又由于线速度和角速度的量纲不同，采用分别考虑的方法，并综合考虑速度和力的传递性，优化结构参数。本文在灵活工作空间内以雅克比矩阵的行列式值作为评价指标，验证当定平台和动平台都是均布时机构是否处于奇异位形，并在整个工作空间中搜索大大减少对并联机床奇异位形分析的工作量。通过对国内外误差建模方法的综述分析，本文采用了矩阵法建立了并联机床机构的误差模型。利用蒙特卡洛技术模拟分析了驱动杆杆长误差和球铰(虎克铰)间隙对终端平台误差的影响。更多还原

【Abstract】 The thesis analyses the kinematics, dexterity, singularity and accuracy of a 5 axis standing virtual CNC machine tool which is based on a novel 5-DOF parallel mechanism systematically.The constitutes and characteristic of the PMT is introduced. The degree of freedom of the mechanism is calculated using formula of the degree of freedom and screw theory respectively. The kinematics analyses of the constraint limb and driving limbs are taken in. The inverse kinematics solution of the driving limbs is given.Velocity Jacobian matrix and force Jacobian matrix of the PMT are educed. The condition numbers of the Jacobian matrix are analyzed to judge velocity transfer performance and force transfer performance between joint space and working space. The three dimensions drawings are drew by Matlab to make analysis visual. Judge flexible workspace using optimizing performance and checking isotropy of flexible workspace’s boundary. Because the measurements of the linear velocity and the angular velocity are different, they are considered respectively. The velocity transfer performance and the force transfer performance are considered synthetically to optimize configuration parameters.When the joints’ distribution of the fixed platform and the moving platform are equal, judge the location is or not singularity. Regard the determinant values of the Jacobian matrix in flexible workspace as estimate guideline, which reduces extremely calculation that has been implemented in the singularity analyses of the 5-DOF parallel mechanism.Analyze errors modeling methods at home and abroad, and erect errors model of the parallel mechanism using matrix methods. The influence of legs’ tolerance and spherical joints’ (Huke joints) clearance on errors of terminal platform is analyzed using Monte-Carlo technique.更多还原