Singularity Analysis for 3-DOF Reconfigurable Robots

A 3-DOF reconfigurable robot model is presented with the reconfigurable parameters related to the joint types and the selection of joint positive directions. The Jacobian matrix is developed using the Vukobratovié-Potkonjak's method, and the singularity regions are derived through the determinant of the related 3×3 Jacobian matrix. Eight groups of the 3-DOF kinematic structure (TTT, TTR, TRT, RTT, TRR, RTR, RRT, and RRR) are analyzed separately, and the singular configurations of each group are given in detail.