Stiffness-based modelling of a hydraulically-actuated soft robotics manipulator

This work investigates the applicability of stiffness-based modelling in soft robotics manipulation. The methodology is introduced and applied to model a soft robotics manipulator as single 3d Timoshenko beam element. The model is then utilized to solve the forward kinematics problem for the manipulator. The algorithm is validated comparing the simulated deflection with the deflection of the physical manipulator for two defined pressure sequences. It is shown that the model behaves in a highly similar fashion in comparison to the manipulator. For both trajectories the maximum position error is close to 6 mm while the error in orientation not more than 18°. The methodology as described in this work reveals great applicability to the field of soft robots being limited only by the stiffness matrix assembly for the given system. Implementations of inverse kinematics and the effects of external force applications are effectively integrable in the described theory.