Handling Granular, Rocky & Natural Media
Granular and rocky matter is commonplace on Earth, as well as the surfaces of the Moon and Mars. We model granular and rocky physical interactions as a means to design and control novel ground systems for autonomous and remote operation.
< Back to previous pageTaking inspiration from mountaineers, we equipped a robot with ice axes that it uses to grip onto hard surfaces. It was tested on a glacier, as well as on freshwater ice in the lab. A model developed to predict gripper performance based on the energy stored by the spring-loaded spikes prior to impact help predict performance observed both in the lab and in the field. Because the gripper is making its own asperities on which to grip, if it doesn’t have enough energy it doesn’t fracture the surface enough. After generating asperities, then it must select a grasp force — without breaking the ice! — to maximize holding/anchoring force.
Fracture-based grasping: dynamic impact enables predictable robotic anchoring to freshwater ice
The gripper uses dynamic impact to grip onto the Mer de Glace glacier.
Prior work also studied the use of non-impact spines to grip onto existing surface asperities for rock climbing and coral sampling applications.
Humanoid rock-climber hand: SpinyHand: Contact Load Sharing for a Human-Scale Climbing Robot
Gripper for handling hard plated corals: Gripper Design with Rotation-Constrained Teeth for Mobile Manipulation of Hard, Plating Corals with Human-Portable ROVs
EMerita BUrrowing Robot (EMBUR)
Press release from the College of Engineering media office:
Efficient reciprocating burrowing with anisotropic origami feet
Granular Resistive Force Theory Implementation for Three-Dimensional Trajectories
Open source Matlab code for running this method now published at our Github page (3D RFT link).
Walk-Burrow-Tug: Legged anchoring analysis using RFT-based granular limit surfaces