Design, Prototype, and Performance Assessment of an Autonomous Manipulation System for Mars Sample Recovery Helicopter

This paper presents the design, prototype, andtesting of a 150 g (current best estimate) manipulation systemthat enables Mars Sample Recovery Helicopter (SRH) conceptto autonomously pickup, stow, and drop-off Returnable SampleTube and Glove Assemblies (RGAs) on the surface of Mars nextto the Sample Retrieval Lander (SRL). It consists of a 3 DOFplanar Robotic Arm (RA), a novel 2 DOF Gripper withcompliant fingers, and a Stow Mechanism. Within the plannedMars Sample Return (MSR) campaign, two SRHs would operatein parallel to retrieve and transfer total of 10 RGAs (146g each)to the SRL, as the backup to the Perseverance Rover. Once SRHarrives at the target pickup location, the RA places the Gripperprecisely over the RGA. The gripper grabs and picks up RGAsusing a linkage based non-back-drivable mechanism and itscompliant fingers. Subsequently, the RA is secured into the stowfeatures, following dislodging rocks and pebbles, by goingthrough a specific sequence of joint trajectories. This ensures theRA and RGA are stable and secure during transit to the SRLwhile all Manipulation System actuators are powered off. Thewhole sequence of manipulation is performed autonomouslyusing feedback of a pair of stereo-cameras and absoluteencoders. Experimental evaluation of the Manipulation Systemperformance has proved its robustness and consistency insuccessful RGA pickup, stow, and drop-off.