Design and Integration of a Multi-arm Installation Robot Demonstrator for orbital large Assembly

Abstract

Space facilities for orbital exploitation and exploration missions are increasingly requiring larger structure to extend their capabilities. Dimensions of future scientific outposts, solar stations and telescopes undoubtedly matter to expand our horizons, power our planet or explore the universe. Due to the foreseen large structures for such applications, a single self-deploying piece contained in standard launcher fairings might become inadequate. Another approach is that large structures could be broken down into standard modules that will be built in-orbit. Assembling large structure in space is particularly challenging but the raise of key enablers as standard interconnects and advanced robotics opens a new horizon for such applications. It is assumed here that the large spacecraft structure and modules are equipped with standard interconnects (SI) that allow them to be mated to each other and to the robot system for manipulation/transport/installation, or to allow the robot system to move across them. This paper introduces the concept of a novel Multi-Arm Robot (MAR) dedicated to on-orbit large telescope assembly, its ground equivalent laboratory demonstrator design and preliminary hardware integration. The MAR is a modular robot composed of three robotic subsystems - a torso and two symmetrical 7-degree of freedom (DOF) anthropomorphic arms with non-spherical wrists - that are functionally independent and can be connected by the means of Standard Interconnects. The modular approach of the MAR reduces the complexity of the different robotic appendages and offers a set of robotic configuration that extends the range of possible operations and provides an intrinsic system redundancy that reduces the overall mission risk. To assess the MAR concept, a Technology Readiness Level (TRL) 4 ground demonstrator, has been designed to provide a framework that allows the multi-arm robot to execute its overall scope of operations in a ground laboratory environment. It comprises a testbed (dummy spacecraft structure, home base, storage area and mobile payloads) offering a space representative environment, a mission control center (computer, simulator and electrical/data support equipment) supervising the MAR's tasks, and a gravity compensation system (gantry crane and offloading system) for supporting the robot under 1-g.