Rahul's Portfolio

Concept

Mission Statement

"VERTEX is the Space Systems Lab's latest and most advanced roving vehicle aiming to ease the exploration burden of Extravehicular Activities (EVAs) on the lunar and Martian surfaces. Specifically, VERTEX is the highly-capable mobility chassis that supports the BioBot concept which combines this rover with a 5-meter umbilical tending planar manipulator and a lightweight, highly mobile spacesuit simulator." - Charles Hanner

Objectives

Primary

Traverse harsh lunar landscapes
Extend EVAs by providing more lifesupport to astronaut
Explore novel suspension designs for lunar terrain vechicles
Autonomous navigation and control for automated exploration

Secondary

Support NASA with future development of lunar terrain vechicles
Assist in advanced spacesuit & robotics development
Act as an analog testbed for future lunar terrain vechicle research

Bonus

Provide students an unqiue oppertunity to work with hardware & software to hone their skills beyond class

Concept of Operations

Vertex/Biobot on its maiden field test tailing the astronaut, Meredith Embrey , providing life support via its umbilical during an EVA simulation.

The Rover

Hardware

Me when I realized I accidently multiplied all the wheel angles by -1 during the maiden field test. (I swear I totally know how to do math)

Specs

Rover:

Vehicle Mass: 2,600 lbs

Payload Capacity: ~1,000 lbs

Top Speed: 20 mph

Slope climbing ability: 30 degrees

Fully Electric: 96V DC, 300A continuous, LiFeMnPO4 batteries
Suspension:

Pitch Range: 28.5 degrees

Roll Range: 40 degrees

24V electric linear actuator driven, coilover suspension offloading

Chassis able to raise over 50 inches high and lay low on the ground

Series elastic actuator for spring-damping
Steering:

Four wheel independent steering and drive

Brushless DC motor and 100:1 Harmonic Drive actuator

Incremental and Absolute Encoders

+-180 degree steering on each wheel

For more on the rover hardware, check out Charlie's website and youtube channel:

The Team

Students

Charles Hanner : Project Lead and Hardware
Nicolas Bolatto : Hardware
Ryan Mahon : Hardware
Spencer Quizon : Hardware
Meredith Embrey : Space Suit
Daniil Gribok : Electronics
Romeo Perlstein : Rover Software & ARVR Suit Software
Rahul Vishnoi : Rover Software

Faculty

Dr. David Akin : Principal Investigator

My Software Contributions / Implementations

I started this project as the sole software developer. As it grew, more people joined, but I built most of the ROS1 implementation myself. It had some bugs, but was a great learning experience. The ROS1 code is now deprecated, as the university required a move to ROS2 with the upgrade to Ubuntu 22.04. The ROS2 port is led by Romeo Perlstein. The cFS implementation was a side project, but it runs best on the rover and now serves as backup "golden" software for quick boots.

Learn More: NASA cFS Implementation
Learn More: ROS1 Implementation
Learn More: AI Components

Publications & Posters

Bolatto, N., Fink, R., Martin, J., Lachance, Z., Vishnoi, R., & Akin, D. (2022, July). Development of an Autonomous Umbilical Tending System for Rover-Supported Surface EVAs. 51st International Conference on Environmental Systems.
Link to paper
Note to add posters here too

Vertex/Biobot