摘要
The non-overconstrained 3-degrees of freedom（DOF） translational parallel mechanism（TPM） has received much attention due to its advantages in reduced cost of fabrication and assembly. Researches are being conducted in the area of type synthesis, kinematic analysis and dimensional synthesis. Mobility, constraint singularity and isotropy of a 3-PRRRR non-overconstrained TPM are studied, where P denote the prismatic pair, R the revolute pair and the overline indicates the same axis direction of the kinematic pair The different arrangements of the three limbs affect the kinematic performance of this kind of TPM. First, the mobility analysis, actuation selection, and the constraint singularity of the general 3-PRRRR TPM are conducted based on screw theory. For a general 3-PRRRR TPM, the three prismatic pairs cannot be chosen as actuators and two kinds of constraint singularities are identified. In the first constraint singularity, the moving platform has four instantaneous DOFs. In the second constraint singularity, the moving platform has five instantaneous DOFs. Then, an orthogonal 3-PRRRR TPM is proposed, which can be actuated by three prismatic pairs and has no constraint singularities. Further, the forward and inverse kinematic analysis of the orthogonal TPM are presented. The input-output equations of the orthogonal TPM are totally decoupled. The full isotropy of the orthogonal TPM is proved by establishing the Jacobian matrix , which is an identity 3x3 diagonal matrix in the whole workspace. The orthogonal 3-PRRRR TPM has great potential in application like fast pick-and-place manipulator, parallel machine and micro-motion manipulator.
The non-overconstrained 3-degrees of freedom（DOF） translational parallel mechanism（TPM） has received much attention due to its advantages in reduced cost of fabrication and assembly. Researches are being conducted in the area of type synthesis, kinematic analysis and dimensional synthesis. Mobility, constraint singularity and isotropy of a 3-PRRRR non-overconstrained TPM are studied, where P denote the prismatic pair, R the revolute pair and the overline indicates the same axis direction of the kinematic pair The different arrangements of the three limbs affect the kinematic performance of this kind of TPM. First, the mobility analysis, actuation selection, and the constraint singularity of the general 3-PRRRR TPM are conducted based on screw theory. For a general 3-PRRRR TPM, the three prismatic pairs cannot be chosen as actuators and two kinds of constraint singularities are identified. In the first constraint singularity, the moving platform has four instantaneous DOFs. In the second constraint singularity, the moving platform has five instantaneous DOFs. Then, an orthogonal 3-PRRRR TPM is proposed, which can be actuated by three prismatic pairs and has no constraint singularities. Further, the forward and inverse kinematic analysis of the orthogonal TPM are presented. The input-output equations of the orthogonal TPM are totally decoupled. The full isotropy of the orthogonal TPM is proved by establishing the Jacobian matrix , which is an identity 3x3 diagonal matrix in the whole workspace. The orthogonal 3-PRRRR TPM has great potential in application like fast pick-and-place manipulator, parallel machine and micro-motion manipulator.
基金
supported by National Natural Science Foundation of China (Grant No. 50605055)
作者简介
CHEN Qiaohong, born in 1978, is currently a lecturer and a PhD candidate in Zhejiang Sci-Tech University, China. She received her bachelor and master degrees in Yanshan University, China. Her research interests include robotics and mechanism theory of parallel manipulators. Tel： ＋86-571-86843364; E-mail： cheny9258@163.comLI Qinchuan, born in 1975, is currently a professor in Zhejiang Sci-Tech University, China. He received his PhD degree on mechanism design and theory in Yanshan University, China, in 2003. His research interests include mechanism theory of parallel manipulators and application. Tel： ＋86-571-86843364; E-mail： lqchuan@zstu.edu.cnWU Chuanyu, born in 1976, is currently a professor in Zhejiang Sci-Tech University, China. He received his PhD degree on mechanism design and theory in Zhejiang University, China, in 2003. His research interests include mechanism theory of agricultural machine and robotics. Tel： ＋86-571-86843352; E-mail： cywu@zstu.edu.cnLI Yi, born in 1973, is currently a lecturer in Zhejiang Sci-Tech University, China. Her research interests include mechatronics and machine design theory. Tel： ＋86-571-86843349; E-mail： liyi0511@163.com
