An Analytical Contact Model for Design of Compliant Fingers

Abstract

A compliant gripper gains its dextral manipulation by the flexural motion of its fingers. It is a preferable device as compared to grippers with multijoint actuations because of reduced fabrication complexity and increased structural reliability. The prediction of contact forces and deflected shape are essential to the design of a compliant finger. A formulation based on nonlinear constrained minimization is presented to analyze contact problems of compliant fingers. The deflections by flexural and shear deformations are both considered. For a planar finger, this formulation further reduces the domain of discretization by one dimension. Hence, it offers a simpler formulation and is computationally more efficient than other methods such as finite element analysis. This method is rather generic and can facilitate design analysis and optimization of compliant fingers. We illustrate some of these attractive features with two types of compliant fingers, one for object handling and the other for snap-fit assembly applications.