Launch Adapter Ring Capture Tool - WVRTChq.wvrtc.com/ICRA2015/posters/ratti.pdf · MDA’s Launch...

ABSTRACTMDA’s Launch Adapter Ring Capture Tool1 is a purpose built robotic tooldesigned to provide the key technology necessary to address the challenges

associated with autonomously grasping an unprepared and uncooperativespacecraft with a robotic arm.

CONCLUSIONS

MDA has successfully developed and demonstrated to TRL-4 the technologynecessary for the reliable capture/attachment to an unprepared anduncooperative space object via its launch adapter ring. The ability to performautonomous grappling is an enabling technology for future satellite servicingand active debris removal missions.

For additional information please contact:

John RattiProduct Development Manager, Orbital Robotics

MDA Robotics and Automationjohn.ratti@mdacorporation.com

ACKNOWLEDGEMENTS:

This work was sponsored by the Canadian Space Agency

MOTIVATIONWith the wide variety of objects that currently populate the orbital debrisenvironment, one of the key challenges facing missions which aspire to

perform active debris removal of large intact debris (spent upper stages andnon-operational satellites such as Envisat) is determining exactly how to safelyapply the necessary forces to a target in order to relocate it into a graveyard oratmospheric re-entry orbit. The use of a robotic arm provides the benefits ofmaneuverability (allowing the arm to accommodate residual relative rates

between the uncooperative target and the servicing spacecraft) andcontrollability/safety (by establishing a rigid link between the two vehicles aftercapture). Unfortunately, none of the orbital debris have been designed with on-orbit capture or servicing in mind, so the robotic capture must be achievedusing a natural feature available on the target. Finding such a feature that is

suitable for capture using a robotic arm is a challenge.

METHODOLOGYOne of MDA’s approaches to capturing an unprepared spacecraft is to grapplethe vehicle’s payload adapter/restraint interface (also referred to as the Launch

Adapter Ring/LAR) as this interface is an excellent mechanical interface due itsadherence to standards for dimensions and strength and because they areguaranteed to have no thermal blankets or other obstructions in the way thatcould otherwise impede capture.

Prototyping and developing an engineering development unit LAR capture toolenabled integrated testing to be performed with a 1g robotic test facility and anair-bearing mounted LAR assembly in order to validate the design anddemonstrate tool’s functional and performance capabilities.

Objective Capability Achieved

Compatibility Adaptive features in the two jaws permit the tool to capture multiple style (profile and diameter) launch adapter rings (LAR)

Misalignment Sensors Integrated vision system for 6 DOF relativepose estimation to support autonomous robotic track and capture operations

Ready for Capture Sensing Contactless sensors detect when a LAR is within the capture envelope of the tool

Capture Envelope ±22mm and ±2.4º in each axis

Capture Time <100ms to achieve topological capture8-12 seconds to achieve a rigid interface

Load Capacity 200 Nm about each axis

Mass < 15 kg

Table 1: Key Capabilities and Performance

Richard Rembala

Launch Adapter Ring Capture Tool

Canadian Robotic Technology for the Autonomous Capture

of Unprepared and Non-Operational Debris

1. US Patent Pending #61/987,860