학술논문

Automated Routing of Muscle Fibers for Soft Robots
Document Type
Periodical
Source
IEEE Transactions on Robotics IEEE Trans. Robot. Robotics, IEEE Transactions on. 37(3):996-1008 Jun, 2021
Subject
Robotics and Control Systems
Computing and Processing
Components, Circuits, Devices and Systems
Strain
Routing
Shape
Robots
Optimization
Muscles
Actuators
Artificial muscles
equilibrium-constrained design optimization
moving least squares (MLS)-based simulation
soft robotics
Language
ISSN
1552-3098
1941-0468
Abstract
This article introduces a computational approach for routing thin artificial muscle actuators through hyperelastic soft robots, in order to achieve a desired deformation behavior. Provided with a robot design and a set of example deformations, we continuously co-optimize the routing of actuators, and their actuation, to approximate example deformations as closely as possible. We introduce a data-driven model for McKibben muscles, modeling their contraction behavior when embedded in a silicone elastomer matrix. To enable the automated routing, a differentiable hyperelastic material simulation is presented. Because standard finite elements are not differentiable at element boundaries, we implement a moving least squares formulation, making the deformation gradient twice differentiable. Our robots are fabricated in a two-step molding process, with the complex mold design steps automated. While most soft robotic designs utilize bending, we study the use of our technique in approximating twisting deformations on a bar example. To demonstrate the efficacy of our technique in soft robotic design, we show a continuum robot, a tentacle, and a four-legged walking robot.