Development of a Flexible Propulsion Mechanism Using a Braided Structure of Metal Plate for a Lunar Exploration Drilling Robot

In previous studies on drilling robots for lunar exploration, it has been challenging for robots to create adequately sized boreholes and achieve significant depth during drilling. In this study, we are endeavoring to develop a lunar drilling robot named “LEAVO,” designed in a worm-like configuration, with the purpose of drilling holes to accommodate environmental sensors and to collect samples from targeted layers. LEAVO has successfully excavated vertically to a depth exceeding 938 mm, thereby validating its efficacy for the initial mission objective. Nevertheless, the current propulsion unit of LEAVO lacks the capability to adequately maneuver around or grip onto curved or uneven surfaces. Therefore, this paper proposes a new propulsion mechanism using Braid structure of metal plate to realize curved surface excavation for the second target mission. In order to verify whether this unit can move while gripping, moving tests were conducted on horizontal, vertical, and tapered pipes. From the experimental results, it is clear that this propulsion mechanism and current-controlled peristaltic motion are useful for various types of pipes.