Towards grasping in unstructured environments: optimization of grasper compliance and configuration

This paper examines the role of grasper compliance and kinematic configuration in unstructured environments, where object size and location may not be well known. A grasper consisting of two two-link planar fingers with compliant revolute joints was simulated as it passively deflects during contact with a target object. The kinematic configuration and joint stiffness values of the grasper were varied in order to maximize grasper workspace for a wide range of target object size. The results show a near-optimal result around the spring-rest angles of 25 and 45 degrees for the base and intermediate joints, respectively, when the joint stiffness ratio (base/intermediate) was small.