Design and optimization of a PKM for micromanipulation

The actual miniaturization trend, present in several industrial sectors, requires high performance capabilities in micromanipulation and assembly. A complete automation of these operations, by means of robots, could result in a significant cost cut in the final product. In this work we present the mechatronic design and optimization of a 3 d.o.f. Delta type PKM for micromanipulation. Starting from a reference task (pick and place with high stroke rate) the optimal links length has been determined by considering several kinematic performance indexes; afterwards the actual link sizing has been performed considering dynamic loading, also taking into account the effect of the links flexibility on end effector trajectory. A direct drive actuation has been chosen, where the motor sizing has been performed to satisfy several criteria: maximum and r.m.s. torque and maximum speed. The motor selection has been speeded up querying a database built by collecting data from the catalogues of several producer. Furthermore robot joints have been carefully designed in order to reduce backlash and friction.