A Static Modelling and Evaluation Framework for Soft Continuum Robots with Reinforced Chambers

Elastomer-based soft manipulators with fibre-reinforced chambers, represent a prevalent design paradigm in soft robotics. These robots incorporate multiple actuation chambers, enabling elongation and bending motions. However, the inherent compliance of materials and the pressurised chambers inevitably introduce significant nonlinearity to these robots. Moreover, design of such robots often relies on a trial-and-error approach. Consequently, a comprehensive robot prototyping framework is of paramount importance. To achieve this, we present a static modelling, design and evaluation framework for soft robots with densely reinforced chambers (i.e., the angle between the reinforcement fibre and the axial direction of soft robots is 90°). We first propose a static analytical modelling framework to achieve both the forward kinematics and the tip force generation modelling. This modelling framework accommodates the effects of pressurised chambers and (non)linear material behaviours. Furthermore, our design and evaluation framework incorporates an open-accessible simulation toolbox with a user-friendly graphical interface, along with a physical evaluation platform. The entire framework is validated by eight kinds of manipulators with varying diameters and lengths. Meanwhile, the nonlinearity introduced by geometrical deformation resulting from the elongation, the pressurised actuation chambers (i.e., the chamber stiffening effect), and material hyper-elasticity are investigated. Results also enable informed decision-making on design specifications prior to robot fabrication.