Abstract: Based on the analyses of workspace, dexterity, velocity and precision, an optimal kinematic design method of 2-DOF planar parallel robot is developed. A global index composed of conditioning index, velocity and precision is proposed to achieve a workspace with good performance. The proposed method can be implemented in two steps. In the first step, under the constraints of dexterity and singularity, a workspace with good performance is achieved, and a set of bars’ length pa-rameters and length ratios of two bars are generated to achieve the objective workspace. In the second step, the proposed global index is used to choose the most optimal length ratio between proximal and distal bars from the series of parameters acquired in the first step, thus the singularity, dexterity, velocity and precision are considered in the optimal design.

Key words: Kinematics, Optimal design, Parallel mechanism