Design and Kinetostatic Analysis of PneuNets-Actuated Compliant Mechanisms for Soft Robots

Designing soft robots is challenging due to their infinite degrees of freedom and high flexibility, which limits their payload capacity. This paper presents a systematic framework for designing and analyzing compliant mechanisms driven by PneuNets bending actuators. The stiffness ratio of the compliant mechanism allows soft robots to carry higher payloads. We design two compliant joints–revolute and prismatic–and verify them through finite element simulations and physical prototypes. A kinetostatic model for the single joint, based on machine learning and the Pseudo-rigid-body model, is developed and integrated into the robotic system. A 3R planar robotic arm is used to evaluate the design and analysis models. The results show that the error of the kinetostatic model is below 5%, and the robotic arm can continuously control target positions with an error of less than 0.5.