Motiv Space Systems, Inc. ("Motiv") is proposing a new design for a contamination tolerant tool-changer for use on lunar and other off-Earth missions that employ a robotic arm with a modest complexity end-effector payload (i.e., not an MSL-class payload). Past missions such as Phoenix and InSight are examples of missions with robotic arms that in retrospect could accommodate such a tool-changer. Future missions with a similar class of robotic arms include the lunar COLDArm, a Technology Payload for the Commercial Lunar Payload Services (CLPS) suite of mission opportunities, and exploratory missions to the surfaces of the Ocean Worlds, comets, and asteroids. For these missions, a tool-changer would enable the robotic arm to perform a more complicated suite of activities such as scooping, gripping, grinding, and debris removal, all using separate tools that are swapped onto the arm as needed. This SBIR addresses a major problem with tool-changing mechanism designs in general, in that they are comprised of mechanical and electrical coupling elements that are sensitive to contamination. Contamination can result in failure to couple or jamming upon release, along with intermittent or broken electrical continuity. Because robotic arm end-effectors are likely to interact with the surface (and subsurface) of the Moon, Mars, or other planetary bodies, contamination problems are inevitable, the Moon in particular because the regolith particles are small, sharp, and prone to attachment because of the Moon's static electricity buildup. Motiv's tool-changer design will allow contamination to collect on mechanical and electrical coupling features and surfaces, but not preclude normal functioning of the tool-changer beyond some loss of positional repeatability when the various tools are exchanged. Electrical functionality will be preserved via self-cleaning of the electrical contacts during the tool exchange cycles
Potential applications for the contamination tolerant tool changer are missions with in-situ robotic arm activities in which the arm requires end-effector tools or instrumentation of modest complexity, particularly regarding electrical signal count. These missions would benefit from the additional flexibility that exchangeable tools offers. The contamination tolerance of the design would allow for its use on the Moon, Mars, the Ocean Worlds, comets, and asteroids, all of which are known to have environments rich in contaminating particulates.
A contamination tolerant tool-changer would be a useful part of terrestrial robotic arm systems, particularly those incorporated into mobile robotic platforms that perform hazardous duties or serve in hazardous environments. Tool exchange flexibility and worn or malfunctioning tool replacement would mitigate the time needed for human interaction, expanding uninterrupted service time