Optimal design of a 2-DOF pick-and-place parallel robot using dynamic performance indices and angular constraints

• An approach for the dynamically optimal design of a parallel robot is presented.
• Two novel normalized dynamic performance indices are proposed for minimization.
• The transmission capabilities are represented by two types of pressure angles
• The pressure angles are regarded as kinematic constraints to prevent singularities.

This paper presents an approach for the optimal design of a 2-DOF translational pick-and-place parallel robot. By taking account of the normalized inertial and centrifugal/Coriolis torques of a single actuated joint, two global dynamic performance indices are proposed for minimization. The pressure angles within a limb and between two limbs are considered as the kinematic constraints to prevent direct and indirect singularities. These considerations together form a multi-objective optimization problem that can then be solved by the modified goal attainment method. A numerical example is discussed. A number of robots designed by this approach have been integrated into production lines for carton packing in the pharmaceutical industry.