COBRA

Crater Observing Bio-Inspired Rolling Articulator

Dust Mitigation Mechanical Engineer

Project Overview

NASA's 2022 Big Idea Challenge asked students to design, develop, and demonstrate robotic systems with alternative rover locomotion for use in extreme lunar terrain. This was motivated by the potentially large concentrations of water-ice in Lunar PSRs (Permanently Shadowed Regions) at the South pole that are currently inaccessible by current rovers to deduce precise locations. Under SEDS (Students for the Exploration and Development of Space), my team of 11 tackled this by creating COBRA: Crater Observing Bioinspired Rolling Articulator
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My Objective

To protect our system from outside dust/particles

My Contributions

As the team's dust mitigation engineer, I ideate protective measures for our COBRA system. This entails materials research with testing schematic creation and conduction as well as overall design generation to maintain our sheath's protective qualities during COBRA's unique transformative movements.

At the competition, we used a neoprene sheath that successfully protected our system in sidewinding, spiral, and hex locomotion.

Beyond this, I was the Media Lead who storyboarded, filmed, and edited our Final Testing Video (hands featured are yours truly):

Sheath Design Flow

Competition System

September 2022- November 2022

Constraints:
To Allow for full movement of all 11 modules in all locomotion/geometries
To Prevent regolith/dust from entering the system
Doesn't cause the system to overheat or to seize

Challenges:
Materials research
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Why A Single-Sheath?
Originally, our team was going to pursue either a single-sheath or a bellow-jointed sheath idea. Ultimately, we went with a single-sheath as the idea of having individual sheaths for each module had both increased complexity and chances of failure.

Primary Research:
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Synthetic polymers such as neoprene and nylon were looked into as well as space-grade fabrics like Kevlar and Vectran. These were chosen due to their highly durable and abrasion-resistant properties and applications.

Due to supply chain issues, neoprene was the chosen fabric for our first iteration of COBRA.
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Final Materials:

A: All Neoprene Samples
B: 3 mm Neoprene
C: 2 mm Neoprene
D: Closed Cell Neoprene
E: 3 mm Neoprene Sheath on COBRA
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Successes:
‍The system was able to engage in it's sidewinding and crawl locomotion as well as its spiral and hex geometries with minimal dust interference. This included a ~50 meter ~28 degree tumble down a rocky mountain.

Needs Improvement / In Progress:
After the tumble mentioned above, parts of the system did poke small holes into the neoprene. We also had not ideated a way to integrate the sheath with the full system. The main idea was for attachments at the head and tail modules to cinch the ends of the sheath. For the tail module's attachment, I began designing SOLIDWORKS CAD of an Iris Door Mechanism as seen on the right.

"As for the tail and its female cavity, an iris diaphragm concept has been ideated to act as a door...For this mechanism, a co-centered outer ring is turned by a servo with respect to an inner ring, which turns the iris blades between them. One end of each iris blade is attached to the outer ring by a pivot assembly and the other to the inner ring by a slider assembly. Thus, as the outer ring turns, the blades will both slide and turn to either open up or close off the cavity to allow the head to enter and exit with minimal regolith interference." (Final Technical Paper)