Performance and geometrical advantage of monolithic two-finger passive structure soft grippers for object grasping

Abstract

In the context of Industry 4.0 robotics is a key technology, as this enables further automation and optimization of production processes. Research of soft grippers is about making robotic systems more versatile. The main contribution of this work is to study the effect of modifications in geometrical parameters, while maintaining constant material and topology, on the geometrical advantage of a monolithic two-finger passive structure with external motors soft gripper design. Geometrical advantage is a quantitative way to relate output displacement and input displacement in a dimensionless ratio of them. The gripper is studied via nonlinear finite element analysis (FEA) simulation, and experimental tests. The digital model predicts how the several variations of the gripper will behave in different situations. Then, experimental test confirms the simulation results with differences ranging from 3.7% to 7.9% error. The experimental test is conducted following the surface response methodology (SRM). Thus, an empirical model that describe the behavior of the grippers’ geometrical advantage in terms of width and length of a bending element on the gripper is obtained. The result show that the grippers are capable to grasp objects of various shapes and sizes. These findings suggest that soft robotic grippers can be studied within a virtual environment entirely. Allowing soft grippers to be made to suit Industry 4.0, leading to smarter, more responsive manufacturing.