A deployable and inflatable robotic arm concept for aerospace applications

The interest in soft systems for space missions represents a growing trend in recent years. The development of inflatable robots, combined with the improvement of deployment mechanisms, allows to build novel lightweight and deployable robotic manipulators. In several space applications, the use of soft robots could minimize bulk and mass, reducing space mission costs. The main challenges in soft robotics are the control of the system and the exertion of high forces. In this manuscript, the concept of an inflatable manipulator with two inflatable links and three degrees of freedom is proposed. After a review about the possible materials to be used for the inflatable parts, the robot mechanical structure, the deploying strategy and the pneumatic line are presented. Then, an elastostatic approach is proposed to model the robot with the aim of developing its control. The last section shows preliminary experimental tests performed on the link prototype with the purpose to evaluate a static characterization in relation to the supplied pressure. Results suggest the validity of the adopted approach to model the system and clarify the pressure influence about the system performances. The study puts the basis for the development of the first prototype of the robotic system.