Topology optimization in designing of anthropomorphic gripper for a robot

Abstract

Application of bionic design methods in robotics can provide structures with unique decorative and functional properties, since natural structures copied by designer are highly rational in the volume distribution of structural material, ensuring at the same time sufficient strength, rigidity and flexibility. The additive technologies, developed in recent years, allow the designer to manufacture complicated parts of a robot and transfer elements of bionic design to them. In this work, a three-finger gripping device for a fruit sorting robot was designed, taking into account the desired anthropomorphic geometry. Methods of topology optimization and special finite-element (FE) modules of ANSYS software were used to improve design of the gripper. For the task of topology optimization, the finger weight was assigned as the target parameter and minimized under loading conditions, so that high strength and stiffness characteristics of the improved geometry were maintained. As an efficient result, weight minimization reduces the required power of compact drives located on moving parts of the structure. Increase in FE mesh density at each next optimization step allows to form bionic features in the finger geometry and approach anthropomorphic design. Eventually, the optimized fingers of gripper were 3D-printed, which seems impossible to manufacture on CNC machines.