Session: 07-11-01 Mobile Robots and Unmanned Ground Vehicles I

Paper Number: 68623

Start Time: Tuesday, 01:20 PM

68623 - Autonomously Controlled Robot With Trilateration-Based Localization for Optimized Excavation of Lunar Regolith 

This work proposes an autonomously controlled robot with trilateration-based localization for optimized excavation of lunar regolith. Extracting local resources from the excavated lunar regolith will help support a sustainable presence on the Moon. For example, there is a supply of water ice beneath the lunar permanently shadowed region. This water ice can be processed into liquid oxygen/hydrogen propellant. The availability of space acquired propellant could dramatically decrease the cost of Earth to space transportation. Therefore, successful excavation of lunar regolith is critical to acquiring this water ice.

To address this need, this work presents a proof-of-concept design for an autonomous lunar mining rover. The autonomous rover is capable of traveling to known dig sites, excavating lunar regolith/water ice simulant, and transporting the lunar regolith/water ice simulant back to a collection sieve, without the need for user input. The rover utilizes ultra-wideband wireless communication devices for localization. These devices enable a steady stream of rover locations that are determined relative to a collector bin, while in range, without relying on line-of-site measurements or ideal lighting conditions. This is particularly useful in scenarios where incorrect or delayed localization results can lead to critical failure in an unsalvageable environment, especially when autonomous rover operation is needed.

The work included a requirements and planning phase, conceptual design (with consideration of design alternatives), detailed design, and testing for performance validation. Computational based simulations were performed to analyze the design and experimental testing planned to validate that the performance requirements are satisfied. The autonomous rover design supports three primary operation modes for excavation/mining, transit, and depositing. For optimization between strength, weight, and cost, the structural design consists of a rectangular aluminum base frame that joins the chassis and mining systems together via mechanical fasteners. The chassis system comprises two key subsystems, the rocker-bogie and stabilization system. The mining system also comprises two key subsystems, the drum chain-drive and the extended conveyor systems. The design provides flexibility to accommodate navigation of different obstacles. A rocker-bogie suspension system allows the rover to move through depressions and over protrusions on the lunar surface, so the rover’s movement is not dependent on a uniform surface. For stability while depositing excavated material, stabilizer legs provide front support to the rover. The stabilizer legs are only activated when depositing material to avoid interference during transit and mining operations. The feet of the stabilizer legs are designed to conform to the surface topography. To support optimal mining capacity, a drum chain-drive provides the rover with the capability of excavating to a maximum achievable mining depth. To maximize the amount of lunar regolith/water ice simulant deposited after mining, the design includes an inward extension to the conveyor system to reduce the possibility of material being lost during the depositing operation (i.e., the extension catches material that does not follow the ideal trajectory onto the main conveyor section when depositing).

Contributions of the proposed design include an autonomously controlled rover for excavation of lunar regolith, with design optimization to maximize the amount of successfully deposited material. The proposed design offers an optimal balance between opposing cost functions and design constraints for reducing the size and weight of the rover, while maximizing the operational performance of the rover for mining, transit, and depositing.

Presenting Author: Michael Smith UNC Charlotte

Authors:

Michael Smith UNC Charlotte
David Grabowsky UNC Charlotte
Holden Stanley UNC Charlotte
Jeremy Brake UNC Charlotte
Aidan Browne UNC Charlotte