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

Abstract

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 payloads (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. K E Y W O R D Sautonomy, dual arm force control, mobile manipulation, space robotics stand the feasibility of the assembly problem of a modular space structure. This is essentially a study of the balance between hardware complexity/tolerances and required autonomous robotic capabilities to achieve subcentimeter assembly.

Technology development and trends of in-space assembled telescope

“…Therefore, it's necessary to carry out co-phase detection on the primary mirror, and use actuators to correct the piston/tip-tilt error, which can make sure the primary mirror corrected from mm-class to λ/30rms [26] , the technical method of wavefront detection and control technology is shown in the figure below. For ISAT, the truss structure should have a very compact launch package to meet the upward launch requirements, provide sufficient stiffness and stability for in-orbit deployment (such as the truss structure similar to the sandwich plate design), besides, each truss module should be equipped with standardized interfaces (such as the addition of multiple nut design at the node position or loose bolt preloading for module connection), easy module-to-module assembly, while the module can be suitable for multi-task and multi-scene construction needs [27] . Truss stability related technologies are shown in the table below.…”

Material–Robot System for Assembly of Discrete Cellular Structures

“…UAVs guided by LiDAR assemble magnetically connected struts and nodes [22] or passively stacked bricks [23], though these systems have a bounded work envelope. For systems without global positioning, localized laser scanning [24] or optical camera fiducial recognition [25] can be used for bricks or truss modules, respectively. In order to reduce sensing complexity, tactile or IR sensors can be used to recognize local positioning markers, while robot movement is assisted by passive geometric alignment features.…”

Guidance and Control Systems for Multi-Satellite Assembly using Decentralized Nonlinear Model Predictive Control

“…It requires expensive equipment and has limitations on mass and size. In addition, a failure of the satellite system leads to a failure of the entire mission [1]. In-orbitassembly (ISA) technology provides an optimal method for performing these missions, in which multiple small satellites replace a large satellite with the same functionality but lower launching costs.…”