Gravity-independent mobility and drilling on natural rock using microspines

Abstract

To grip rocks on the surfaces of asteroids and comets, and to grip the cliff faces and lava tubes of Mars, a 250 mm diameter omni-directional anchor is presented that utilizes a hierarchical array of claws with suspension flexures, called microspines, to create fast, strong attachment. Prototypes have been demonstrated on vesicular basalt and a'a lava rock supporting forces in all directions away from the rock. Each anchor can support >160 N tangent, >150 N at 45 • , and >180 N normal to the surface of the rock. A two-actuator selectivelycompliant ankle interfaces these anchors to the Lemur IIB robot for climbing trials. A rotary percussive drill was also integrated into the anchor, demonstrating self-contained rock coring regardless of gravitational orientation. As a harderthan-zero-g proof of concept, 20mm diameter boreholes were drilled 83 mm deep in vesicular basalt samples, retaining a 12 mm diameter rock core in 3-6 pieces while in an inverted configuration, literally drilling into the ceiling.

A novel universal gripper based on meshed pin array

“…NASA has developed the microspine gripper. 24,25 It utilizes a hierarchical, radially symmetric array of claws with suspension flexures, to perform omnidirectional gripping. Wang et al have proposed a linearly constrained microspine array mechanism, 26 which is capable of overcoming strong shear forces on rough terrain under an appropriate normal force.…”

Gravity Independent Climbing Robot: Technology Demonstration and Mission Scenario Development

“…With this design, only 80 potential attachment points and a single level of compliance were realized, but similar performance was achieved on volcanic rocks. 4 Two gravity-independent drills were also developed, shown in Figures 7 and 8. The microspine anchors are able to react the forces of sampling by redirecting them back into the rock.…”

Hovering of MAV by using magnetic adhesion and winch mechanisms

“…In Sections III and IV, we describe mechanisms mounted on an MAV. In Section V, we show TABLE I COMPARISON OF ADHESION METHODS (++:FAVORABLE, +:LITTLE FAVORABLE, -:SLIGHTLY UNFAVORABLE, −−:UNFAVORABLE) adhesion low power adhesion force continuous less danger attaching to method consumption for weight using to surroundings diverse substance negative pressure [4], [5] -++ ++ + ++ magnetic adhesion [6], [7] ++ ++ ++ ++ −− micro spines [8] ++ + ++ -+ electrical adhesion [9], [10] + -+ -++ adhesive pad [11], [12] ++ + -+ -biomimetics [13], [14] ++ --+ -how an MAV can adhere to a ceiling, lower itself on a tether, and observe objects.…”

“…In addition, we have added a new function by which an MAV approaches a target object from above by using a winch mechanism. Many approaches have been proposed for adhering to walls and ceilings: negative pressure [4], [5], magnetic adhesion [6], [7], micro spines [8], electrical adhesion [9], [10], adhesive pad [11], [12], and biomimetics [13], [14]. Our target environment is industrial plants and damaged buildings.…”