Sustainable Operation of Autonomous Systems
Autonomous In-Air Battery Swapping
Limited battery capacity often requires unmanned aerial vehicles to interrupt their missions and return to the ground for recharging or battery replacement. We develop autonomous in-air battery swapping systems that replenish a vehicle’s energy while it remains airborne. Our approach integrates cooperative rendezvous planning, precise docking guidance and control, and a mechanical battery-exchange mechanism carried by a supplier drone. The planning and control framework coordinates collision-free trajectories and maintains a stable docking approach despite aerodynamic interactions between the vehicles. Outdoor flight experiments demonstrate autonomous rendezvous, docking, and battery exchange, providing a practical foundation for extended-duration aerial operations without ground returns for the receiving vehicle.
Selected publication:
Y. Choi*, J. Henson*, K. Keller*, C. Gamble*, A. Kini*, and R. Dai. "A Mid-Air Autonomous Battery Exchange Aerial System." IEEE Robotics and Automation Letters, Vol. 11, No.7, 2026, pp. 8108-8115. DOI: 10.1109/LRA.2026.3693549
Mission Planning for A Multi-robot Team with Solar-Powered Charging Station
The video shows path plans and power allocation schedules designed for a multi-robot team in our indoor test environment. It includes a clip of three UGVs executing the planned paths accompanied with time-synchronized plots of each vehicle’s power and energy trends. In the first 35-40 seconds, all UGVs travel to the assigned objective points. The charging station will also harvest energy when traveling to its assigned points. In the remaining time, all UGVs rendezvous at the final point and the charging station charges the worker UGVs through the magnetic charging connectors. At the end of the mission, all assigned points are visited and each UGV obtains net energy gain.
Selected Publication:
N. Kingry*, Y. Liu*, M. Martinez*, B. Simon*, Y. Bang*, and R. Dai, "Mission planning for multi-robot team with a solar-powered charging station", 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Vancouver, CA, September, 2017. DOI: 10.1109/IROS.2017.8206413
Integrated Path Planning and Power Management for Solar-Powered Unmanned Ground Vehicles
This video begins with a brief objective summary and then presents a visualization of the scalar field construction process. Next, the video shows a path plan and power allocation schedule designed by the modified particle swarm optimization (PSO) for the indoor test environment, followed by a clip of a UGV executing the planned path with real-time tracked power and energy history. A comparative result following the same path under constant speed is provided to verify the improved performance from PSO algorithm.
Selected Publication:
1. A. Kaplan*, N. Kingry*, P. Uhing*, and R. Dai, "Time-Optimal Path Planning with Power Schedules for a Solar-Powered Ground Robot", IEEE Transactions on Automation Science and Engineering, Vol. 14, No.4, pp. 1235-1244, 2017. DOI: 10.1109/TASE.2016.2533418
2. A. Kaplan*, N. Kingery*, J. Ven Den Top*, K. Patel*, R. Dai and D. Grymin, "Motion Planning for Persistent Traveling Solar-Powered Unmanned Ground Vehicles", IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Daejeon, Korea, Oct. 2016. DOI: 10.1109/IROS.2016.7759496
Design, Modeling and Control of a Solar-Powered Quadcopter
This video presents the design, modeling, control, and experimental test of a solar-powered quadcopter to allow for long-endurance missions. We present the design of a large-scale quadcopter that incorporates solar energy harvesting capabilities. Based on the design results, we built the dynamical model of the customized quadcopter with analysis of the aerodynamic influence. A feedback control system is developed for the solar-powered quadcopter that takes into account the wind disturbance and is verified in virtual simulation examples. Flight tests with the prototype are presented to validate the theoretical basis of the solar-powered quadcopter.
Selected Publication:
N. Kingry*, L. Towers*, Y. Liu*, Y. Zu*, Y. Wang*, B. Staheli*, Y. Katagiri*, S. Cook*, and R. Dai, "Design, Modeling and Control of a Solar-Powered Quadcopter", 2018 IEEE International Conference on Robotics and Automation (ICRA), Brisbane, Australia. DOI: 10.1109/ICRA.2018.8462896