Fin Ray Crossbeam Angles for Efficient Foot Design for Energy‐Efficient Robot Locomotion

Abstract

Robot foot and gripper structures with compliancy using different mechanical solutions have been developed to enhance proper contact formations and gripping on various substrates. The Fin Ray structure is one of the solutions. Although the Fin Ray effect has been proposed and exploited, no detailed investigation has been conducted on the effect of different crossbeam angles inside its frame. Thus, herein, an integrative approach is used, combining 3D printing with soft material, finite element modeling, and neural control to 1) manufacture the Fin Ray structure with compliancy; 2) investigate the effect of different crossbeam angles under different loads and cylindrical substrates; and 3) finally apply it as an efficient compliant robot foot structure for energy‐efficient on‐pipe locomotion. Considering the factors of a large contact area, high energy efficiency, and better durability, the Fin Ray model with nonstandard 10°‐inclined crossbeams provides the best compromise in comparison with other models, within the constraints of the defined geometric parameters.

GelSight Fin Ray: Incorporating Tactile Sensing into a Soft Compliant Robotic Gripper

“…The Fin Ray has a simple structure consisting of two long fin bones and several horizontal ribs, which are 3D printable and easy to modify [5], [6]. Over the years, the Fin Ray structure has been successfully applied to many robotic tasks using its adaptive geometry [5], [7].…”

Variable Stiffness, Sensing, and Healing in FESTO’s FinRay Gripper: An Industry-Driven Design

“…The FESTO finger have challenges with handling delicate objects due to the stiffness of its material and structure [12]. Structural optimizations have been researched to tune the stiffness of FinRay grippers [13], [14], as well as introducing a two-state discrete variable stiffness through a snap-fit mechanism [15]. Although no external component needs to be added to the gripper with structural optimization, this approach has limitations in changing the stiffness, specifically in a controlled and continuous manner.…”

Analysis of Contact Force and Shape Change on Grasping a Square Object Using an Actual Fin Ray Soft Gripper

“…For example, Elgeneidy et al [ 11 ] reported the ability to change the stiffness of the Fin Ray structure due to contact between crossbeams by changing the angle and arrangement of the crossbeams. Manoonpong et al [ 12 ] used a Fin Ray structure for the feet of a multi-legged mobile robot and verified the angle at which it becomes stable on each uneven terrain by changing the crossbeam angle. This FEM has shown some degree of success in terms of demonstrating the grasping performance of the FRSG model in the simulation.…”