Study on kinematic characteristics and singularities of a 3-DOF parallel robot

Kinematic characteristics of a 3-DOF parallel robot 3-PRS are studied through a new method and its particular style of the three DOFs and relationships between the three DOFs and the other three DOFs are obtained through analysis of mechanism constrains. Square Jacobian matrix of the parallel robot is got by the velocity polygon vector function method and differential relations of the motion platform axes. Then the singularity of the 3-PRS parallel robot is analyzed by the Jacobian matrix and tested by the vector relationships between the motion platform and the rod. Finally, specific method is given out to avoid singularities.