Physical safety analysis of robot considering impactor shape

Abstract

This paper proposes an approach to estimate the physical safety of robot in the case of collision with a human by evaluating the contact force and the contact pressure at the surface of the collision which are considered the sole factors that cause the injury. Establishing a nonlinear dynamic collision model we developed a human skin model as a layered contact model with nonlinear elasticity. Also the shape of the impactor (which means the robot part colliding with the human body) is modeled in unlike the previous researches where the effect of the impactor shape is ignored to simplify the analysis by modeling the robot as a point mass. In addition the effect of the inertial distribution of the robot towards the collision is analyzed and modeled using a recursive method. In this paper, a set of nonlinear equations derived from the nonlinear dynamic collision model is solved numerically and simulation results of estimated impact pressure and force during the collision are presented.