Continuation-Based Design of Self-Contacting Soft Robotic Manipulators

Abstract

We create a design tool that allows for modeling the behavior of soft robotic manipulators consisting of serially concatenated, fiber-reinforced elastomeric enclosures (FREEs) as they are pressurized. This tool uses numerical continuation to solve the governing multisegment boundary-value problem as the actuation pressure is varied, accounting for self-contacts via imposition of constraint normal forces. The methodology highlights limitations of existing design techniques for multisegment FREEs that only consider the configuration at the final pressure; achieving complicated tasks such as self-knotting may require considering self-contact in the design process. It is also shown that multiple equilibrium shapes of a multisegment FREE can co-exist across ranges of the actuation pressure. At the extremes of such ranges, we anticipate that small changes in the actuation pressure will result in large changes to the manipulator configuration during pressurization.KeywordsKirchhoff modelboundary-value problemself-contactbifurcations