Analysis of Rigid-Flexible Coupling Characteristics of Pneumatic Modular Soft Joints with Variable Stiffness

Abstract

This paper proposes a new pneumatic modular joint to address the problem of balancing compliance and load-bearing capacity for soft robots. The joint possesses characteristics that allow for omnidirectional deformation and dynamically adjustable stiffness. In this study, mathematical models were established to describe the deformation and stiffness variability of the joint. Corresponding relationships between gas pressure and deformation and magnetic field strength and module stiffness were derived through numerical analysis. Finite element simulations were conducted to investigate the changes in pressure and deformation under different stiffness conditions and the changes in magnetic field strength and joint stiffness under various deformation states. Finally, experimental validation was performed to verify the theoretical calculations and simulation results, demonstrating excellent coupling characteristics between stiffness and compliance for the proposed joint.