Human–robotic symbiosis to enable future planetary extravehicular activity

Abstract

This paper presents the concept of a morphing upper torso, a pressure suit design which incorporates robotic elements to enable a resizable, highly mobile and easy to don/doff spacesuit. The torso is modeled as a system of interconnected parallel manipulators, which allows the critical suit dimensions to be reconfigured to match the wearer. The back hatch of a rear-entry torso is interconnected with the waist ring, helmet ring and two scye bearings. Half-scale and full-scale experimental models are used along with analytical models to examine the implications of ring interconnections, the role of external forces generated by pressurized fabric, and the mobility of the system. The kinematics of the system are calculated, and the Jacobian matrix for the robotic system, which relates the total twist vector of the system to the vector of actuator velocities, is derived. This analysis enables quantification of the actuator requirements, given demanded trajectories of the rings. The analytical and experimental results demonstrate that the torso components can be accurately repositioned to different desired configurations. The results show that the torso could be expanded to facilitate donning and doffing, and then contracted to match different wearer's body dimensions. The demonstrated feasibility of the morphing upper torso concept makes it an exciting candidate for inclusion in a future planetary suit architecture.