Design and Experiments of a Robotic Arm with a Rigid-Soft Coupling Structure*

Aiming at the insufficient load capacity of a soft robot, a robotic arm based on rigid-soft coupling structure was proposed. It is composed of fluidic soft actuators external installed and a rigid skeleton in central. The stiffness variation of the skeleton is realized by using jamming principle. The rigid skeleton is a Y-shaped linkage mechanism, which can realize bending and elongation simultaneously. This coupling structure has the same degrees of freedom in comparison with the original three-chamber soft robotic arm without the rigid skeleton. A prototype of the robotic arm as well as an experimental setup were developed. Load capacity experiments and dynamic response experiments of the robotic arm were implemented respectively. The results verify that the proposed rigid-soft coupling robotic arm is superior to the skeletonless soft robotic arm in terms of load-carrying capacity and dynamic response performance.