Robotic Actuators for Cryogenic Environments (RACE)

Motiv Space Systems is proposing the Robotic Actuator for Cryogenic Environments (RACE) to address the growing need for precision, high specific-torque robotic arm actuators for operations in extreme temperature environments such as permanently shadowed regions (PSRs), Enceladus, or other icy moons. For such missions, a premium is placed on low energy consumption, and RACE decreases actuator energy usage by improving efficiency and eliminating the need for actuator heaters. RACE is a novel approach to cryogenic actuators that is easily scalable and modular by design. RACE leverages Motiv’s work developing BMG material components for planetary gearboxes with the Distributed Extreme Environments Drive System (DEEDS) SBIR Phase II Sequential program and will implement a single-pass cycloidal reducer as the output stage. RACE is a heater-free, BMG material-based actuator with a small cycloidal output stage driven by a brushless DC gearmotor. Motiv and the PI have extensive experience with the design, analysis, assembly, integration, and qualification of rotary actuators for space robotics. Motiv developed and delivered all the joint actuators for the Mars 2020 Perseverance Rover robotic arm and, most recently, the COLDArm system. Construction of the motor and planetary gearbox is based on that developed for the Cold Operable Lunar Deployable Arm (COLDArm). Both COLDArm and DEEDS feature BMG material components to enable operation at -180°C, and both programs introduced BMG material elements as “drop-in” substitutions for mechanism components typically made of standard materials that comprise Motiv’s designs. Bulk Metallic Glass is an amorphous metal which has properties of high strength and low wear under load without the supplement of lubricants. Motiv is in a unique position to apply BMG substitutions to the cycloidal architecture to improve manufacturability of extreme environment rotary actuators and develop a scalable family of actuator products.