4PRR-P混联加工机构运动学研究

Kinematics Study of 4PRR-P Hybrid Machining Mechanism

由于平面并联机构存在着动平台灵活度低,容易产生机构奇异,工作空间小等缺点,课题组提出了一种新型4PRR-P混联加工机构。基于螺旋理论验证了机构的自由度特征,建立了机构位置逆解数学模型,确定了机构的奇异位形。采用数值搜索法求解了机构的工作空间,通过考察各尺度参数对工作空间的影响,优选得到了机构的关键尺度参数。相关数值计算及运动仿真结果表明该机构可以解决平面并联机构存在的灵活度低、容易产生机构奇异、工作空间小等问题。文中运动学模型及性能分析结论合理正确,相关成果可为机构动力学分析、结构设计提供参考。

Because of the shortcomings of planar parallel mechanism,such as low flexibility of moving platform, singularity of mechanism and small workspace,a new 4PRR-P hybrid machining mechanism was proposed in this paper. Based on the screw theory,the DOF characteristics of the mechanism were verified,and the inverse solution mathematical model of the mechanism position was established,and the singular shape of the mechanism was determined. The workspace of the mechanism was solved by numerical search method. The key dimension parameters of the mechanism were optimized by investigating the influence of dimension parameters on the workspace. Relevant numerical calculation and motion simulation results show that the mechanism can solve the problems of low flexibility,singularity and small workspace of planar parallel mechanism. The kinematics model and performance analysis conclusion in this paper are reasonable and correct,and the relevant results can provide a reference for the dynamic analysis and structural design of the mechanism.