An Inflatable Robotic Assistant for Onboard Applications

In recent years, robots are evolving to collaborate with humans sharing the same workspace. In space missions, human and robotic partnership is now essential, especially in onboard activities. Collaborative robots have the possibility to work in strict contact with humans, thanks to their gentle design and the limitations on the speed. In limited working areas, soft robots are considered an interesting possibility because the intrinsic feature of softness of their structure allows to work with users more safely. In this paper, the concept of an inflatable and lightweight onboard robotic assistant is proposed. The robot consists of two inflatable links and three actuated joints. It can be stored in a relatively small package, if compared to its extended configuration, to be deployed on demand for working activities. The links are expected to have built-in sensors, as flex sensors, inertial measurement units and cameras, that are used to estimate the robot state, using sensor fusion techniques. The behavior of the inflatable links is described through a pseudo-rigid body model, considering non-linearities introduced by the presence of possible wrinkles. A prototype of the link is realized and characterized throughout static and dynamic tests, analyzing the effect of internal pressure. Evaluations about achievable payloads, weights and dimensions of the robot are exhibited. Results suggest the feasibility of the project, putting the basis for the development of the overall system.