Payload-centric autonomy for in-space robotic assembly of modular space structures

摘要

The paper addresses the problem of constructing large space structures (~100 m) by using autonomous robots to assemble modular components in space. We are motivated by the problem of creating space structures at a scale greater than what is feasible with a single self-deploying design. We had two goals in this work. The first was to investigate and demonstrate the feasibility of long-order multitask autonomy. The second was to study the balance between required tolerances in hardware design and robotic autonomy. This paper reports on a payload-centric autonomy paradigm and presents results from laboratory demonstrations of automated assembly of structures using a multilimbed robotic platform. We present results with deployable 20 lb pay-loads (1 m trusses) that are robotically assembled to form a 3-m diameter kinematically closed loop structure to subcentimeter accuracy. The robot uses its limbs to deploy the stowed modular structural components, manipulate them in free space, and assemble them via dual-arm force control. We report on results and lessons learned from multiple successful end-to-end in-lab demonstrations of autonomous truss assembly with JPL's RoboSimian robot originally developed for the Defense Advanced Research Projects Agency (DARPA). Videos of these demonstrations can be seen at https://goo.gl/muNLJp (JPL, 2017). Each end-to-end run took precisely 26 min to execute with very little variance across runs. We present changes/improvements to the RoboSimian system post-DARPA Robotics Challenge (DRC) (Karumanchi et al., 2016). The new architecture has been improved with a focus on scalable autonomy as opposed to semiautonomy as required at the DRC.