混联机构结合了串、并联机构的优点,已经越来越多地应用在复杂自由曲面零件的加工装备中。提出一种能够实现一个移动和两个转动的3自由度并联3-PSP机构,同时该机构存在伴生运动。通过对3-PSP机构运动模式的分析,简化传统的欧拉角描述方式,采用更适合的倾斜—扭转角描述动平台的运动。在此基础上,建立运动学模型,进行包括伴生运动和被动关节变量的完整运动学求解。基于运动学分析,对3-PSP机构的关节行程、速度特性和精度特性进行分析,证明该机构完全适用于混联结构中的并联模块,并能够满足航空、航天、汽车等领域复杂零件的加工需要。
Hybrid series-parallel mechanism, which contains the advantages of both series and parallel mechanisms, is used more and more widely in the manufacturing equipment for parts with complex free curved face. A 3-DOF parallel 3-PSP mechanism, which can realize one translational and two rotational motions, is proposed. The 3-PSP mechanism has accompanying motions. According to the analysis of motion mode, tilt-torsion angle for describing the motion of moving platform is adopted instead of traditional Euler angle, and based on that, kinematic model is built to solve the complete kinematic problem including accompanying motions and passive joint variables. Furthermore, the range of the joint, velocity characteristic, and accuracy characteristic are analyzed to demonstrate that the 3-PSP mechanism is fully suitable for parallel module in hybrid series-parallel frame which can fulfill the requirement of the complex parts in aerial, space, and automotive fields.