Abstract— With a growing number of applications in the world for UAVs, there is a clear limitation regarding the need for extended battery life. With the current flight times, many users would benefit greatly with an innovative option of field charging these devices. The objective of this project is to investigate feasibility of inductively harvesting energy from a power line cable for applications such as charging a UAV drone. Research investigates a dual hook perching device that securely attaches to a power cable and aligns an inductive core with the cable for harvesting energy from its electro-magnetic field. Modeling and analysis of the core highlights critical design parameters, leading to evaluation of circular, semi-cylindrical, and u-shaped prototypes designed to interface with a 1” power cable. Underactuated two jaw manipulators at each end of the coil are proposed for grasping the cable and aligning it with the charging coil, ultimately providing a firm grasp and perch. An open source hexacopter drone was used in this study to integrate with the charging novelty. The results provided can be used as a starting point to study the reliability of this method of charging and to further investigate perching abilities of UAVs. I. INTRODUCTION There are an increasing number of UAV applications in the industrial sector. Such applications include surveying, imaging, mapping, inspecting, filming, plant and wildlife preservation, agriculture, atmospheric science monitoring, and computer vision to name a few. A major limitation that effects almost all UAVs is their operation time due to their battery life. This limits their flight time and data collecting ability and normally requires human intervention to replenish the batteries. Ideally, UAVs could harvest energy from their environment to recharge and continue operation for extended periods of time. Toward this goal, this research presents a system allowing aerial vehicles to perch on a power line and harvest energy. Mounted on top of a UAV, Figure 1, the proposed perching mechanisms allow the UAV to hang from the power cable while also mating a U-shaped inductive coil with the powerline. The coil can then harvest energy from the AC magnetic field emitted by the powerline due to current passing through the cable. Two perching mechanisms on either side of the inductive coil provide a firm and stable grasp on the power cable. This allows the UAV to passively hang from the cable, using no energy for perching, while also gathering energy through the coil. The long-term goal is to operate equipment, such as environmental sensors, and charge onboard batteries. This paper contributes design and evaluation of the perching and energy harvesting system, and demonstrates their application to a small multi-rotor vehicle. Analysis highlights how design variables affect inductive coil capability, which is validated via several coil prototypes highlighting balancing between magnetic permeability, weight, and size. Vehicle size and load capacity limit the size and capability of the charging system. Design and analysis of the perching mechanism is also contributed; perching mechanisms allow a wide opening to simplify alignment with the cable, while actuation causes the mechanism to pull the cable into the inductive coil and grasp it firmly. The mechanism is designed to remain closed around the cable without power applied to the actuator. Experiments evaluate performance of the resulting system. The paper is structured as follows. Sec. II describes work related to this research and helps frame its contributions. Sec. III provides a description of the overall system and indicates specific details of the vehicle platform that constrain the Design and Evaluation of a Perching Hexacopter Drone for Energy Harvesting from Power Lines Ryan Kitchen, Nick Bierwolf, Sean Harbertson, Brage Platt, Dean Owen, Klaus Griessmann and Mark A. Minor, IEEE Member This work was supported by the University of Utah. R. Kitchen, N. Bierwolf, S. Harbertson, B. Platt, D. Owen, and K. Griessmann were with the University of Utah, Salt Lake City, UT 84112. 1 M.A. Minor is with the University of Utah, Salt Lake City, UT 84112 USA (Corresponding author, email: mark.minor@utah.edu). Figure 1. Perching system and inductive coil supporting a hex-a-rotor attached to a power cable. 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) October 25-29, 2020, Las Vegas, NV, USA (Virtual) 978-1-7281-6211-9/20/$31.00 ©2020 IEEE 1192