From Ground to Space-Based Robotic Assembly Dr. Maximo A. Roa, PMP - PowerPoint PPT Presentation

From Ground to Space-Based Robotic Assembly Dr. Maximo A. Roa, PMP Institute of Robotics and Mechatronics German Aerospace Center - DLR Workshop: Robotic Technology for In-Space Assembly ICRA 2019 May 23, 2019

I. OOS/R/A MISSIONS

Why ISA? Solar electric power Space dock servicing facility Asteroid redirect vehicle High definition space telescope Surface ISRU Artificial gravity vehicle [Belvin et al., 2016] Atmospheric deccelerators Star shades

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) Robonaut (NASA/GM) General service and maintenance Monitoring and cleaning tasks RRM – Robotic Refueling Mission (2009-2017)

Current missions RESTORE-L (NASA) PHOENIX (DARPA,USNL), FREND program

DEOS mission - DLR DEOS: Deutsche Orbital Servicing Mission

OOS-SIM facility https://www.youtube.com/watch?v=ruLLYIjGOKQ

II. PROJECTS

EU space projects – Space Robotics SRC

PULSAR: Prototype of an Ultra-Large Structure Assembly Robot

PULSAR: Prototype of an Ultra-Large Structure Assembly Robot Scientific questions: • How did we come to be? • Are Earth-like planets common? • Are we alone? • …

PULSAR: Prototype of an Ultra-Large Structure Assembly Robot

PULSAR: Prototype of an Ultra-Large Structure Assembly Robot

PULSAR: Prototype of an Ultra-Large Structure Assembly Robot Foldable structures Fairing limitations James Webb Space Telescope https://www.youtube.com/watch?v=bWw5EOKYHd4 Ariane 6

PULSAR: Prototype of an Ultra-Large Structure Assembly Robot Demonstrators: - dPAMT, demonstrator of Precise Assembly of Mirror (physical) dLSAFFE , demonstrator of - Large Structure Assembly in Free Floating Environment (physical) dISAS, demonstrator of In- - Space Assembly in Simulation (virtual)

PULSAR: Prototype of an Ultra-Large Structure Assembly Robot dPAMT, demonstrator of Precise Assembly of Mirror (physical) Requirements: -Assembly of 5 min. mirror tiles -Functional demonstration of mirror (adapt optical surfaces) Challenges: -1G conditions -Standard interconnections between elements -Assembly, grasp, motion planning -Perception, visual servoing

MOSAR: Modular Spacecraft Assembly and Reconfiguration

MOSAR: Modular Spacecraft Assembly and Reconfiguration Scenario 1: Assembly of 6 SMs Scenario 2: Replacement of a defective module

Existing robotic arms Canadarm 2 (SSRMS) ERA JEM-RMS Feature SSRMS JEM-RMS ERA Base ISS ISS ISS DoF 7 12 7 Length 17.6m 12.2m 11.3m Mass 1800 kg 970 kg 630 kg Year 2001 2008 2019?

Standard interfaces iSSI (iBOSS) Housing Guiding petals Cover lids Latching End Effector (LEE) Spindles Latch APM IF / main structure Actuator Pockets Capture tab SIROM

III. GROUND-BASED AUTONOMOUS ASSEMBLY

Flexible assembly using a modular construction set Maschinenbau Kitz GmbH FMS Montagetechnik GmbH Item Industrietechnik 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

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

Conceptional Skill Execution Flow

Exemplary Skill Sequence for the insert_slot_nut Task Start PickUpGroupFromStorage PlacePegInHole PickUpGroupFromStorage Finish PlaceSlotNutIntoProfile MoveSlotNutIntoProfile PickUpAndPlaceGroupIn AssemblyFixture.

Skill Robustness through Sensor-Based Execution PlaceObject PlacePegInHole PickUpScrew

Assembling one-of-a-kind https://www.youtube.com/watch?v=2jYhdmk-pMg [Nottensteiner, Roa et al., ISR’16]

Examples of Assembled Structures

Next step: Dual arm assembly Reachability maps [Porges, Roa et al., ASTRA’15] [Sundaram, Roa et al., HUMANOIDS’16]

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: PROTOTYPICAL demonstrations for in-space assembly  PULSAR: Prototype of an Ultra-Large Structure Assembly Robot  MOSAR: Modular Spacecraft Assembly and Reconfiguration  Multiple challenges: AOCS, walking manipulator, autonomous assembly with standard interfaces, modularity, robustness…

Acknowledgments PULSAR Prototype of an Ultra-Large Structure Assembly Robot www.smerobotics.org/ MOSAR Modular Spacecraft Assembly and Reconfiguration Contact maximo.roa@dlr.de www.robotic.dlr.de/maximo.roa