Robotic Technologies for in-Space Assembly Operations

Máximo A. Roa, Korbinian Nottensteiner, Armin Wedler, Gerhard Grunwald Institute of Robotics and Mechatronics German Aerospace Center - DLR

14th Symp. Advanced Space Technologies in Robotics and Automation - ASTRA June 21, 2017

Why ISA?

-Synergies between OOS/OOA -Larger, leaner structures -Reduced costs -Overcome limitations at lunch time -…

1890 satellites, 240 claims [Krishna et al., 2016]

Asteroid redirect vehicle

Artificial gravity vehicle

Space dock servicing facility

High definition space telescope Surface ISRU

Solar electric power

Star shades Atmospheric deccelerators

Why ISA?

[Belvin et al., 2016]

I. EXISTING TECHNOLOGIES

Standard interfaces

JAXA EE (JAXA) CTED (ESA)

RSGS Interface (MDA)

MDA passive IF (MDA)

DWIM (Tokyo Tech)

First concepts of OOS/A

ARAMIS (NASA, 1983) Space Applications of Automation, Robotics

and Machine Intelligence Systems

OOS/A: Past missions

Engineering Test Satellite VII (NASDA), 1999 First demo on aut. rendezvous and docking

Orbital express (NASA), 2007 First demo of end-to-end robotic servicing (ORU, fluid transfer)

Existing solutions

Dextre (CSA/NASA) General service and maintenance RRM – Robotic Refueling Mission (2009-2017)

Robonaut (NASA/GM) Monitoring and cleaning tasks

(Current) missions

PHOENIX (DARPA,USNL), FREND program

RESTORE-L (NASA)

https://www.youtube.com/watch?v=QQ0mSNsGlcQ

Previous concepts (Phases A/B)

Trusselator 5cm/min (Tethers Unlimited)

SpiderFab (Tethers Unlimited) NASA NIAC grant

https://www.youtube.com/watch?v=Wg6msu6OUNc

Ongoing projects

Dragonfly (Space Systems Loral with Tethers Unlimited) Assembly Large solid RF reflectors

Archinaut (Made in Space) 3D printing Truss structures

Ciras (Orbital ATK) Deployment Solar arrays

NASA “Tipping Point” Program, Emerging Space Capabilities, 2015

DEOS mission - DLR

DEOS: Deutsche Orbital Servicing Mission

OOS-SIM facility

[Artigas et al., ICRA’15]

http://ieeexplore.ieee.org/document/7139588/

II. AUTONOMOUS ROBOTIC ASSEMBLY

Flexible assembly using a modular construction set

Item Industrietechnik GmbH

Maschinenbau Kitz GmbH

FMS Montagetechnik GmbH

Flexible assembly for products from a modular construction set

Automated process Complex geometry Lot size one Easy to use

[Nottensteiner, Roa et al., ISR’16]

Visual Recognition of Desired Assembly

Demonstration by the user Alternative input from CAD

data Visual feedback of process Three phases:

Perceptive Cognitive Assembly specification

End-effectors

Selected gripper

Assembly Sequence Planning

Feasible sequences generated - through analysis of dissassembly Generation of AND/OR graph to

store variants of sequences

Evaluation of graph considering feasibility, preferred mating actions,…

-

Assembly & Grasp Planning

Considered constraints:

Due to the subassembly Due to the joining action

Quality criterion: distance to COM

-

[Thomas, Roa et al., CASE’15]

Task Pattern Classification

Example of a generated sequence Classification of assembly tasks Four major task types:

Insert_slot_nut Add_angle_bracket Add_screw Position_profiles

Classification concept

Skill Library

Conceptional Skill Execution Flow

Exemplary Skill Sequence for the insert_slot_nut Task

PickUpGroupFromStorage PlacePegInHole PickUpGroupFromStorage

PlaceSlotNutIntoProfile MoveSlotNutIntoProfile PickUpAndPlaceGroupInAssemblyFixture.

Start

Finish

Skill Robustness through Sensor-Based Execution

PlaceObject PlacePegInHole PickUpScrew

Assembling one-of-a-kind

[Nottensteiner, Roa et al., ISR’16]

https://www.youtube.com/watch?v=2jYhdmk-pMg

Examples of Assembled Structures

Next step: Dual arm assembly

[Sundaram, Roa et al., HUMANOIDS’16]

Reachability maps

[Porges, Roa et al., ASTRA’15]

Assembling one-of-a-kind in a more flexible way

III. FINAL REMARKS

Keypoints

Demonstration of on-ground robotic assembly technologies Combination of high/medium/low level planning tools allow the automatic generation of complete workflows Active compliance provides a nice control framework for robust executions, coping with uncertainties Ongoing work – dual arm demonstration with extension to 3D structures

Next step: create a relevant demonstration for in-space assembly Micro-gravity Actively regulated platform Dynamic effects of arm motion Effects of physical contact Handling visual occlusions

Acknowledgments

maximo.roa@dlr.de www.robotic.dlr.de/maximo.roa

Dr. Tim Bodenmüller

Andreas Stemmer

Michael Kassecker

Daniel Seidel

Theodoros Stouraitis

Ashok Sundaram

Oliver Porges

Non-DLR:

Dr. Ulrike Thomas (TUC),

Dr. Uwe Zimmermann (KUKA)

Christoph Borst (KUKA)