基于传统的单纯串联机构工作空间大、运动学正解简单的优点,考虑到单纯并联机构结构刚度大、承载能力强、运动学反解简单等特点,参考国际国内有关串并混联机构的研究成果,结合现实加工领域的需要,提出一种全新结构的直角坐标串并联机构。通过线性驱动,它可以实现机构上下层动平台之间的输出主轴空间6自由度运动。通过解析几何作图法,得知机构的工作空间形态为四棱柱或三棱柱,并给出了机构出现奇异时的奇异结构与工作空间形态。机构输出主轴处于空间任一位姿时,运用解析作图法取得输出主轴在三维空间的极限摆角范围,采用该方法还找到了机构运动学一般位置反解的几组可能解。进一步分析可知输出主轴平行于垂直导轨方向时有三组可行解,不平行时有五组可行解。
Based on the merits of pure serial manipulators, such as large working space and simple kinematic forward solution, also the characteristics of pure parallel manipulators, which include high rigidity and better carrying capacity and simple kinematic inverse solution, as well as the fruits about serial-parallel hybrid manipulators overseas and inland, still practical requriements in manufacutring process involved, a new type of universal Cartesian serial-parallel manipulator is presented. 6-DOF(degree of freedom) output shaR between upperlayer and underlayer platform is obtained by linear actuation. Workspace in shape of four-prism or three-prism is established by analytic geometry method, singular structure of mechanism and the shape of singular workspace presented. Litmits of swinging angle of output shaR at given configuration in 3D space are acquired by analytic method. Several groups of inverse solution of position with universal meaning are obtained. Further analyses indicate that there are three groups of solution satisfing the requirements when the output shaft is parallel to the vertical guideway, five groups of solution exist if the output shaft is not parallel to the vertical guideway .