Tag: Rafael Fierro

Autonomous UAVs for Volcanic CO₂ Plume Mapping

UNM MARHES Lab: Dr. Rafael Fierro, Kevin Aubert, Isaac Seslar

UNM Computer Science: Dr. Matthew Fricke, Dr. Jared Saia, Dr. Melanie Moses, John Ericksen (PhD), Abir Islam (PhD), Julie Hayes (PhD), Carter Frost

UNM Earth and Planetary Sciences: Dr. Tobias Fischer, Dr. Scott Nowicki, Karissa Rosenberger (Masters), Samantha Wolf

Rochester Institute of Technology: Varsha Dani (Assistant Professor)

Affiliated Institutes: Santa Fe Institute, NV5

SKETCH Algorithm & Dragonfly UAVs

The team implemented SKETCH, a real-time boundary-tracing algorithm using two UAVs to detect and trace volcanic CO₂ plume edges. One UAV flies inside the plume boundary and another outside, adjusting paths based on real-time gas readings to maintain a “sandwich invariant.” Compared to a baseline single-drone strategy (ZIGZAG), SKETCH offered significant efficiency gains—shorter flight paths, less turning, and faster mapping times—without sacrificing boundary-tracking accuracy.

Field tests were conducted with physical Dragonfly drones in simulated and natural environments, including Balloon Fiesta Park and the Valles Caldera supervolcano in New Mexico. In simulation and real-world scenarios, SKETCH outperformed traditional mapping strategies, demonstrating robust performance even in complex multi-plume structures and narrow “dumbbell” configurations.

Gradient Descent and Rasterization Mapping

Earlier phases of VolCAN demonstrated the Dragonfly swarm’s ability to autonomously follow CO₂ gradients using a modified flocking algorithm, allowing UAVs to collaboratively locate emission sources. Rasterization techniques, including lawnmower and spiral search algorithms, were used for large-area mapping, while Kriging interpolation was applied to create CO₂ concentration heatmaps.

Impact and Future Directions

The VolCAN project reduces the risk to human researchers, improves temporal resolution in gas monitoring, and provides tools for better volcanic eruption prediction. The SKETCH system bridges the theory-implementation gap in autonomous boundary tracing and lays the foundation for future applications in environmental robotics, including hazardous leak detection and industrial monitoring.

For more information, visit: https://volcan.cs.unm.edu/

Papers:
[1] J. Ericksen et al., “Navigating the Edge: UAS Boundary Tracing for Efficient Volcanic Plume Monitoring,” 2024 IEEE International Symposium on Safety Security Rescue Robotics (SSRR), New York, NY, USA, 2024, pp. 52-57, doi: 10.1109/SSRR62954.2024.10770060. keywords: {Accuracy;Navigation;Volcanic activity;Estimation;Turning;Real-time systems;Safety;Security;Monitoring;Testing},

[2] Aerial survey robotics in extreme environments: Mapping volcanic CO2 emissions with flocking UAVs J Ericksen, GM Fricke, S Nowicki, TP Fischer, JC Hayes… – Frontiers in Control Engineering, 2022

November 12, 2024
MORRIS: Safe Time-Coordinated Control for Multi-UAV Systems

UNM Students: Jean-Elie Pierre

Senior Contributors: Dr. Rafael Fierro (UNM), Xiang Sun

In the realm of Advanced Air Mobility (AAM), the ability for multiple autonomous UAVs to arrive at predefined destinations simultaneously is critical—whether to transport heavy payloads cooperatively or to synchronize actions in mission-critical scenarios. However, this task is far from simple. UAVs must navigate complex spatial environments, not only avoiding collisions with each other, but also steering clear of non-cooperative flying objects (NCFOs) that aren’t part of the system.

To tackle this challenge, the MARHES Lab has contributed to the development of MORRIS—the safe terminal tiMe-cOordinated contRolleR for multI-uav Systems. MORRIS is a novel safe linear quadratic optimal control algorithm designed to achieve time-synchronized arrivals while also ensuring collision-free trajectories.

MORRIS is made up of two integrated components:

1. Terminal Time-Coordinated Planner: Calculates optimal acceleration inputs to minimize the timing error between actual and desired arrival times for all UAVs.

2. Safety Layer using Control Barrier Functions (CBFs): Adjusts those acceleration commands to guarantee that the UAVs maintain safe distances from each other and from NCFOs, ensuring real-time collision avoidance.

This layered approach means that MORRIS not only keeps UAVs safely spaced in dynamic environments but also ensures that they complete their missions in perfect temporal coordination.

Papers:
[1] Learning safe multi-uav coordination with temporal-spatial constraints. JE Pierre, X Sun, R Fierro – AIAA SCITECH 2024 Forum, 2024

January 4, 2024
Advancing Aerial Interaction: Fully-Actuated Hexarotor and Omni-Directional Multirotor Platforms
Students: Riley McCarthy, Giovanni Cordova, Isaiah Garcia-Romaine, Daniel McArthur, Emely Seheon, Tristan Thomas

Senior Contributors: Dr. Rafael Fierro

Overview:

The MARHES Lab at the University of New Mexico continues to break new ground in aerial robotics with two groundbreaking actuation projects: the Fully-Actuated Hexarotor and the Omni-Directional Multirotor (Omnicopter). These vehicles, developed as part of Riley McCarthy’s Master’s thesis and supported by both Sandia National Laboratories and the Air Force Research Laboratory, are engineered to transform multirotors from passive inspection tools into platforms capable of active interaction with their environment.

Fully-Actuated Hexarotor

Designed to overcome the limitations of traditional co-planar multirotor drones, the fully-actuated hexarotor uses six strategically oriented propellers to decouple translational and rotational motion—unlocking six degrees of freedom (6 DOF). This allows it to hover, pitch, roll, and translate independently, making it ideal for complex manipulation tasks.

Hardware & Build:

Based on a modified Tarot TL65B01 carbon fiber frame

Equipped with tri-blade 9-inch propellers and 2806.5-1460KV motors

Integrated with an Odroid-XU4 companion computer and a Rokubi Mini force/torque sensor

Controlled via PX4 flight stack and ROS2 Foxy middleware

Testing & Control:

Controlled using a custom PID controller for position and PX4’s built-in attitude controller

Executed trajectory tracking tasks: hovering with pitch/roll offsets, figure-eight paths, and level translation

Showcased force-feedback manipulation via a hybrid position/force controller, enabling wall contact, sustained pushing, and motion during contact using real-time feedback from the Rokubi sensor

Omni-Directional Multirotor (Omnicopter)

Expanding upon the hexarotor’s capabilities, the omnicopter introduces true omni-directionality—it can thrust in any 3D direction, regardless of its orientation. Built for extreme aerial flexibility, this design is well-suited for emulating spacecraft dynamics and next-generation maneuvering.

Hardware & Control:

Features a symmetric design and fixed, non-planar propellers

Uses PX4’s updated control allocation for managing complex thrust vectors

Inputs calculated using the Moore-Penrose pseudo-inverse method for dynamic allocation

Tested extensively in Gazebo simulation and real-world flight using the Vicon system

Experimental Achievements:

Hovering while rotating 360° about multiple axes

Translational motion while spinning in arbitrary orientations

Demonstrated thrust envelope coverage across 3D space

Both of these projects represent major advancements in the control and design of aerial robotic systems. By equipping drones with true six-degree freedom and hybrid force control, the MARHES Lab is opening the door to a future where aerial systems can manipulate objects, interact with surfaces, and perform complex real-world tasks previously reserved for grounded robots.

Papers:
[1] McCarthy, Riley M.. “Control of Fully-Actuated Aerial Manipulators and Omni-Directional Multirotors.” (2023). https://digitalrepository.unm.edu/me_etds/241
December 1, 2023
Adaptive Cable-Based Box Transport with Catenary Robots

UNM Students: Gustavo A. Cardona, Diego S. D’Antonio

Senior Contributors: Dr. Rafael Fierro (UNM), David Saldaña, Claus Danielson

This project introduced a novel cooperative aerial manipulation strategy using two “catenary robots”—each formed by two quadrotors linked by a cable. Rather than attaching cables to a payload, the robots wrap cables around a box and pull it using friction. An adaptive controller compensates for unknown object parameters (mass, inertia, and contact points), enabling autonomous transport of cuboid payloads without human setup. This method provides a flexible, low-intervention solution for package delivery and urban drone logistics.

Papers:
[1] G. A. Cardona, D. S. D’Antonio, R. Fierro and D. Saldaña, “Adaptive Control for Cooperative Aerial Transportation Using Catenary Robots,” 2021 Aerial Robotic Systems Physically Interacting with the Environment (AIRPHARO), Biograd na Moru, Croatia, 2021, pp. 1-8, doi: 10.1109/AIRPHARO52252.2021.9571068. keywords: {Adaptation models;Tensors;Shape;Friction;Transportation;Trajectory;Adaptive control},

October 1, 2021
Swing-Free and Agile Load Transport with Quadrotors

UNM Students: Ivana Palunko, Patricio Cruz

Senior Contributors: Dr. Rafael Fierro (UNM)

This work focused on ensuring safe and agile suspended load transport using quadrotors. Researchers implemented an adaptive controller to handle shifts in the quadrotor’s center of gravity during flight and applied dynamic programming to design swing-free trajectories. This combination allows precise and stable load manipulation even with uncertain dynamics, minimizing swinging motion. Applications include emergency supply delivery, landmine detection, and transport in cluttered environments.

Papers:
[1] I. Palunko, P. Cruz and R. Fierro, “Agile Load Transportation : Safe and Efficient Load Manipulation with Aerial Robots,” in IEEE Robotics & Automation Magazine, vol. 19, no. 3, pp. 69-79, Sept. 2012, doi: 10.1109/MRA.2012.2205617.
keywords: {Unmanned aerial vehicles;Airicraft navigation;Robots;Radio communication;Drones},

September 1, 2012