Every year NASA holds the Robotic Mining Competition (RMC) where universities and colleges compete with their own robot design to mine the most regolith from a mining pit full of regolith covered with BP-1 lunar simulant. The University of North Dakota has been competing in this competition for ten years and has had first place winning robots in the past. After an underwhelming place last year, this year the UND NASA RMC Team is redesigning its robot to mine more regolith, weigh less, and be fully autonomous. This new design will deploy a trenching mining system that will allow the robot to dig toward itself with redesigned buckets that will reduce mining forces. It will also have an active material separation system that will more effectively separate the regolith from the BP-1 and discard the BP-1. The new drive system will involve motors that are substantially lighter, smaller, and less expensive than the ones previously used, while also providing more torque. The robot will also have a new hopper that will more effectively deposit the regolith and have fewer crevices where it can get stuck. The new wheels will be riveted together instead of welded, have chamfered edges on the rim for maneuverability, and have the spokes and ribs running through the rim for structural support. The redesigned robot will also be fully autonomous, itâ€™s electronics will be smaller and fit inside one box, saving weight. Overall this redesign should lead to success in the mining competition.
This report details the work completed by the University of North Dakotaâ€™s team for NASAâ€™s 2019 Robotic Mining Competition. This will be the 10th year that UND has competed. The project provides students with a challenging project whose main goal is to design a robot which can excavate material from the surface of an extraterrestrial planet. Students get engineering project exposure from project structure, design, fabrication and testing. The existing design consists of a bucket ladder which excavates similarly to a bucket ladder dredger. This design performs quite well as the robot can dig very deep in the mining pit. Some down falls are the need to reposition the robot to dig more material as well as the separation of fine material from coarse material.
The robot must fit in size constraints of 1.5m x .75m x .75m. A maximum weight allowed is 80 kg. The mining competition consists of two runs of 10 minutes each. The robot must mine as much of the icy regolith which primarily makes up the bottom 15 cm of the 45 cm mining pit. A minimum of 1kg of icy regolith must be collected and deposited in order to qualify to win the mining portion of the competition. Points are deducted for robot mass, bandwidth usage and energy consumed. Points are rewarded for icy regolith mined, autonomy and dust tolerance.
The criteria for success as defined by the team are as follows:
Â· Mass < 50kg
Â· Mined regolith ~ 25 kg
Â· Average bandwidth < 700 kb/s
Â· Energy consumption < 60 Wh
The fall semester requirements were to design a system which can meet these performance criteria. The following spring semester will be to fabricate and test a system based on the fall semester design to meet the performance criteria. The current status of the project is at a completed design phase transitioning to procurement. Some components have already been purchased and the remaining components will be purchased so that fabrication can begin at the beginning of spring semester.
Recommendations for spring semester are to fully plan out and assign manufacturing tasks and due dates at the start of the semester. This will keep the project on track for early testing. This will allow time to make adjustments and refine the robot’s operation prior to competition.