Shape Optimization of 2D Compliant Links for Design of Inherently Safe Robots

Abstract

In this paper, we represent a preliminary work towards the design of compliant mechanisms for human safe co-robots. We developed a shape optimization framework for design of planar compliant links for inherently safe robotic manipulators. It is well known intentionally introducing compliance to mechanical design can increase safety of robots. However traditional approaches such as elastic joints or uniform compliant links, were either at the cost of significantly reduced performance or with increased extra complexity and cost. Here, we propose a novel method to design compliant robotic links with a safety constraint which is quantified by Head Injury Criterion (HIC). The robotic links are modeled as a 2D beam with a variable width. Given a safety threshold i.e. HIC constraint, the width of the beam is optimized to give a uniform distribution of HIC along the longitudinal direction of the link. Links with a uniform HIC distribution have a better control performance. Finally, this solution is validated by an huamn-robot impact simulation program built in Matlab.