title: Modeling and Analysis of a 2-DOF Spherical Parallel Manipulator.
abstract: The kinematics of a two rotational degrees-of-freedom (DOF) spherical parallel manipulator (SPM) is developed based on the coordinate transformation approach and the cosine rule of a trihedral angle. The angular displacement, angular velocity, and angular acceleration between the actuators and end-effector are thus determined. Moreover, the dynamic model of the 2-DOF SPM is established by using the virtual work principle and the first-order influence coefficient matrix of the manipulator. Eventually, a typical motion plan and simulations are carried out, and the actuating torque needed for these motions are worked out by employing the derived inverse dynamic equations. In addition, an analysis of the mechanical characteristics of the parallel manipulator is made. This study lays a solid base for the control of the 2-DOF SPM, and also provides the possibility of using this kind of spherical manipulator as a 2-DOF orientation, angular velocity, or even torque sensor.
authors.affiliation: Key Laboratory of Electronic Equipment Structure Design, Ministry of Education of China, Xidian University, Xi'an 710126, China. xchduan@xidian.edu.cn.|Collaborative Innovation Center of Information Sensing and Understanding, Xidian University, Xi'an 710126, China. xchduan@xidian.edu.cn.
authors.forename: Xuechao
authors.initials: X
authors.lastname: Duan
authors.affiliation: Key Laboratory of Electronic Equipment Structure Design, Ministry of Education of China, Xidian University, Xi'an 710126, China. yzyang@stu.xidian.edu.cn.
authors.forename: Yongzhi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Laboratory of Electronic Equipment Structure Design, Ministry of Education of China, Xidian University, Xi'an 710126, China. chengbi@stu.xidian.edu.cn.
authors.forename: Bi
authors.initials: B
authors.lastname: Cheng
keywords: dynamics; kinematics; spherical parallel manipulator; virtual work principle