Dynamic Analysis of an Adjustable Torso Design for a Planetary Pressure Suit

The research discussed in this paper demonstrates further advancements in the concept of a Morphing Upper Torso, which incorporates robotic elements within the pressure suit design to enable a resizable, highly mobile and easy to donn/doff spacesuit. A full scale experimental model has been made, which accompanies several analytical models. The Jacobian matrix for the robotic system, which multiplies the total twist vector of the system to yield the vector of actuator velocities, is derived. This dynamic analysis enables quantification of the dynamic actuator requirements, given demanded trajectories of the rings. A motion capture pilot study was done to develop a methodology to obtain measurements of suit movement and hence the ring trajectories. Subjects performed various tasks that a suited astronaut may perform on a planetary surface, while wearing a torso mockup within the motion capture system. This study provides the range of motion and speed requirements for the four, interconnected rings to follow the astronauts motion and provide an enhanced level of mobility. Also discussed is the synthesis of the design and the desire to minimize the number of actuators while still controlling the required degrees of freedom. This research further demonstrates the possibilities for the Morphing Upper Torso concept as a highly mobile, resizable and easy to donn/doff planetary suit.