Kinematic and singularity analysis of symmetrical 2 DOF parallel manipulators

In this paper, an investigation on the kinematics and the singularities of symmetrical 2 degrees of freedom (DOF) planar parallel manipulators is presented. The parallel manipulators considered are composed of five links, five revolute joints and two motors giving input rotation to the system. The forward kinematic and the inverse kinematic models of the parallel manipulators are performed. Jacobian matrices of the parallel manipulators are derived and three types of singularities are identified for them. The results of this paper are very useful for trajectory planning, analysis and control of 2 DOF parallel manipulators.