US Army Readies UGV Charging Ports for Autonomous Drone Swarms

The U.S Army today said a swarm of hundreds of unmanned air vehicles could soon descend on unmanned ground vehicles to autonomously recharge.

The U.S. Army Combat Capabilities Development Command’s Army Research Laboratory awarded the University of Illinois Chicago a four-year, $8 million cooperative agreement in August to develop foundational science in two critical propulsion and power technology areas for powering future families of unmanned aircraft systems, or UASs.

The research, slated to begin this fall, is part of a larger research portfolio of multi-fuel capable hybrid-electric technologies led by the laboratory that supports the Army Modernization Priority for Future Vertical Lift.

This collaborative program will help small battery-powered drones autonomously return from military missions to unmanned ground vehicles for recharging. The university is developing algorithms to enable route planning for multiple teams of small unmanned air and ground vehicles.

Dr. Mike Kweon, program manager for the laboratory’s Versatile Tactical Power and Propulsion Essential Research Program, said the research on route planning is critical to the Army, which needs intelligent, small UASs that can find optimal routes during a military mission to autonomously return to unmanned ground vehicles, known as UGVs, for recharging. This will optimize the operational range extension and time on mission.

“Imagine in the future, the Army deploying a swarm of hundreds or thousands of unmanned aerial systems,” Kweon said. “Each of these systems has only roughly 26 minutes with the current battery technologies to conduct a flight mission and return to their home before they lose battery power, which means all of them could conceivably return at the same time to have their batteries replaced.”

“Soldiers would need to carry a few thousand batteries on missions to facilitate this, which is logistically overwhelming and overall, not conducive to a leading expeditionary military operation,” he said. “With this research project, we’re operationalizing scientific endeavors to increase Soldier readiness on the battlefields of tomorrow.”

The use of fast, recharging batteries and wireless power transfer technologies will allow multiple small UASs to hover around unmanned ground vehicles for wireless charging, and this will not require Soldier involvement. “I believe this is the only way to realize practical UAS swarming, and small UAS and UGV teaming. Without solving how to handle the energy demand, all other advanced technologies using artificial intelligence and machine learning will be useless for the Army,” Kweon said. “On the battlefield, we do not have luxury to replace batteries for 100s of UAVs and recharging them for hours."

For larger drones, Army-funded research will explore the fundamental science needed to develop miniaturized fuel sensors for future multi-fuel hybrid electric propulsion systems.

Fuel property sensors that university partners are developing will help Soldiers who operate fuel-based equipment measure fuel property in real time for the Army’s air and ground vehicles, Kweon said.

This knowledge will allow Army personnel to prevent catastrophic failures of the systems and to increase its performance and reliability.

“This research is critical not only for air vehicles but also ground vehicles, especially for the Army missions,” Kweon said. “The fuel sensor is telling the operator what type of fuel is being delivered from the fuel tank to the engine. This input signal can be used to intelligently tell the engine to adjust engine control parameters according to the fuel type to avoid any failures. This data can also be used to find root-cause failures if any engine component prematurely failed.”

The university’s current research in fuel sensor development examines the effects of fuel structure and chemistry on ignition in future multi-fuel drone engines so that real-time control can be implemented. This project further explores the underpinning science using advanced techniques including spectroscopic diagnostics and data science analysis to both enable and accelerate real-time control.

“It also enriches the understanding of the ignition of any unconventional fuel that may need to be burned in the drone engines,” said Prof. Patrick Lynch, a principal investigator at the University of Illinois Chicago on this project.