Author Information

Is this project an undergraduate, graduate, or faculty project?

Undergraduate

Project Type

individual

Campus

Daytona Beach

Authors' Class Standing

Rithika Nagarajan, Senior

Lead Presenter's Name

Rithika Nagarajan

Lead Presenter's College

DB College of Engineering

Faculty Mentor Name

Dr. David Canales Garcia

Abstract

This project develops an SE(3)-based touchdown dynamics framework to study how lunar landers can remain stable during landing on sloped and uncertain terrain. Safe lunar landing is challenging because uneven load redistribution, slip, and asymmetric sinkage can push the vehicle’s center of mass outside its support polygon, increasing tip-over risk. The purpose of this work is to extend a fixed-leg touchdown model to a multi-joint landing leg system while also examining how varying regolith properties affect landing stability. The method combines coupled rigid-body translation and rotation with per-foot unilateral contact, compliant normal force response, and Coulomb-limited friction to simulate touchdown and settling under lunar gravity. Stability is evaluated using a signed support polygon margin on the terrain plane, while additional outputs such as per-leg reaction forces, penetration depth proxies, lateral kinetic energy, and slip diagnostics are tracked to characterize touchdown behavior. Preliminary results show that lower-friction and softer-compliance regolith cases increase slip frequency, penetration depth, and sensitivity to contact timing, which can reduce stability margins on slopes. The multi-joint leg extension provides a way to modify stance geometry and compliance to improve touchdown robustness under these conditions. This work is significant because it creates a structured simulation framework for design trade studies, autonomy-ready stability maps, and future machine learning models for lunar landing risk prediction.

Did this research project receive funding support (Spark, SURF, Research Abroad, Student Internal Grants, Collaborative, Climbing, or Ignite Grants) from the Office of Undergraduate Research?

No

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SE(3) Touchdown Dynamics with Multi-Joint Landing Legs and Regolith-Dependent Contact for Autonomous Tip-Over Risk Prediction

This project develops an SE(3)-based touchdown dynamics framework to study how lunar landers can remain stable during landing on sloped and uncertain terrain. Safe lunar landing is challenging because uneven load redistribution, slip, and asymmetric sinkage can push the vehicle’s center of mass outside its support polygon, increasing tip-over risk. The purpose of this work is to extend a fixed-leg touchdown model to a multi-joint landing leg system while also examining how varying regolith properties affect landing stability. The method combines coupled rigid-body translation and rotation with per-foot unilateral contact, compliant normal force response, and Coulomb-limited friction to simulate touchdown and settling under lunar gravity. Stability is evaluated using a signed support polygon margin on the terrain plane, while additional outputs such as per-leg reaction forces, penetration depth proxies, lateral kinetic energy, and slip diagnostics are tracked to characterize touchdown behavior. Preliminary results show that lower-friction and softer-compliance regolith cases increase slip frequency, penetration depth, and sensitivity to contact timing, which can reduce stability margins on slopes. The multi-joint leg extension provides a way to modify stance geometry and compliance to improve touchdown robustness under these conditions. This work is significant because it creates a structured simulation framework for design trade studies, autonomy-ready stability maps, and future machine learning models for lunar landing risk prediction.

 

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