Contact force analysis of deformable finger

For robots, gripper designs constitute an important problem. It involves the design of actuation mechanism, gripper fingers and robot-grippers interface. Considering the gripper fingers, it can be hard or a soft one. The soft fingered grippers can handle the objects very efficiently and without causing damage to the object surface. However, the design of soft finger is a difficult task. It consists of material selection, contact force modelling and analysis for different types of grasp, arriving at suitable finger geometry, deciding upon number of joints for the finger, and choosing a proper actuation mechanism. An important contribution of this paper is the development of contact force models for various types of grasps. First, the contact force is determined using finite element analysis. Second, the contact force for circular, triangular and rectangular contacts are determined analytically using models. Third, the contact forces for different types of grasp are determined experimentally. Finally, the contact forces determined by the models and experiments are compared and suggestions are made for the selection of finger geometry.