Presenter Information

Kevin French, RedwireFollow

Session

Technical Session 9: Advanced Technologies III

Location

Utah State University, Logan, UT

Abstract

In Space Manufacturing (ISM) combined with robotic In Space Assembly (ISA) enables autonomous construction of space structures including spin gravity habitation rings, precision synthetic aperture radar (SAR) structures, and trusses for kilometer scale solar sails. Archinaut One (AO), designated as OSAM-2 by NASA, will demonstrate ISM and ISA through the ability to 3D print and robotically manipulate meter scale structures in orbit all from an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) class satellite. This work focuses on challenges associated with autonomous robotic ISA and ISM operations. Limited computational resources, robot satellite coupled dynamics, contact dynamics, and short low bandwidth communication windows are all of major concern. Radiation hardened computational resources significantly lag terrestrial solutions often prohibiting the use of common robotic motion control systems. AO uses distributed computation and highly optimized controllers to accommodate the large computational cost of controlling the 7 degree of freedom robot arm. As a consequence of comparable masses, robot arm motion imparts significant satellite attitude disturbances. AO uses dynamics simulations with carefully pre-planned trajectories, and pre-planned interludes of active and inactive Attitude Control System (ACS) to avoid instability in the ACS, maintain communications and solar power. Contact is required for several ISA tasks, but small motion error can lead to rapid buildup of contact forces endangering critical systems. An admittance controller and strictly enforced speed limits maintain acceptable contact force bounds. AO’s polar orbit and communication hardware limits communications to short low bandwidth windows. AO is endowed with sufficient autonomy required for faster than human-in-the-loop control and between communication windows. This paper discusses the approach toward robotic autonomy required for the AO mission. Modeling, simulations, hardware in the loop simulations, along with several representative ground based tests are outlined and prove the efficacy of these methods.

This paper will discuss the approach toward robotic autonomy required for the AO mission. Modeling and testing are outlined, as well as how the challenges of coupled dynamics, contact dynamics, and autonomy are addressed.

Available for download on Saturday, August 07, 2021

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Aug 12th, 9:00 AM

Advanced Technologies: 7 Degrees of Freedom Robotic Arm on Archinaut One

Utah State University, Logan, UT

In Space Manufacturing (ISM) combined with robotic In Space Assembly (ISA) enables autonomous construction of space structures including spin gravity habitation rings, precision synthetic aperture radar (SAR) structures, and trusses for kilometer scale solar sails. Archinaut One (AO), designated as OSAM-2 by NASA, will demonstrate ISM and ISA through the ability to 3D print and robotically manipulate meter scale structures in orbit all from an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) class satellite. This work focuses on challenges associated with autonomous robotic ISA and ISM operations. Limited computational resources, robot satellite coupled dynamics, contact dynamics, and short low bandwidth communication windows are all of major concern. Radiation hardened computational resources significantly lag terrestrial solutions often prohibiting the use of common robotic motion control systems. AO uses distributed computation and highly optimized controllers to accommodate the large computational cost of controlling the 7 degree of freedom robot arm. As a consequence of comparable masses, robot arm motion imparts significant satellite attitude disturbances. AO uses dynamics simulations with carefully pre-planned trajectories, and pre-planned interludes of active and inactive Attitude Control System (ACS) to avoid instability in the ACS, maintain communications and solar power. Contact is required for several ISA tasks, but small motion error can lead to rapid buildup of contact forces endangering critical systems. An admittance controller and strictly enforced speed limits maintain acceptable contact force bounds. AO’s polar orbit and communication hardware limits communications to short low bandwidth windows. AO is endowed with sufficient autonomy required for faster than human-in-the-loop control and between communication windows. This paper discusses the approach toward robotic autonomy required for the AO mission. Modeling, simulations, hardware in the loop simulations, along with several representative ground based tests are outlined and prove the efficacy of these methods.

This paper will discuss the approach toward robotic autonomy required for the AO mission. Modeling and testing are outlined, as well as how the challenges of coupled dynamics, contact dynamics, and autonomy are addressed.