Optimized design of a rigid kinematic module for antagonistic soft actuation

Abstract

Soft actuators can be useful in human-occupied environments because of their adaptable compliance and light weight. We previously introduced a variation of fluidic soft actuators we call the reverse pneumatic artificial muscle (rPAM), and developed an analytical model to predict its performance both individually and while driving a 1 degree of freedom revolute joint antagonistically. Here, we expand upon this previous work, adding a correction term to improve model performance and using it to perform optimization on the kinematic module dimensions to maximize achievable joint angles. We also offer advances on the joint design to improve its ability to operate at these larger angles. The new joint had a workspace of around ±60°, which was predicted accurately by the improved model.