PowerLine Unmanned Surfer (PLUS): Shape Adaptive Dynamics Development and Control Design

TL;DR

This paper introduces the Powerline Unmanned Surfer (PLUS) concept, which aims to extend fixed‑wing UAV endurance by harvesting energy from overhead power lines and tracking the powerline contour with centimeter‑scale precision. It develops a dynamics framework that blends shape‑adaptive actuation (camber, thickness, and span morphing), aerodynamic forces, and a frequency‑mapping control strategy that ties the Phugoid mode to the powerline’s local catenary frequency via a morphing parameter $\sigma(t)$. The authors derive a catenary model for the powerline, formulate a linearized, shape‑dependent flight‑dynamics representation, and implement a feedforward controller that leverages local spatial frequency matching $\omega_s(x) = \frac{1}{u_0}\omega_t(\sigma)$ to achieve tracking. Experimental thickness morphing identification and extensive simulations show that, for Group I UAVs, less aggressive morphing can yield sub‑meter clearance over substantial portions of a span, with thickness morphing exerting strong influence on Phugoid wavelength and actuation demands being reduced near certain sag conditions. The work offers a foundation for near‑field, energy‑harvesting flight and highlights a potential simplification at very high voltages where advanced morphing may be unnecessary for low‑clearance trajectories.

Abstract

This paper introduces the powerline unmanned surfer (PLUS) concept to extend the limited endurance of fixed wing unmanned aerial vehicles (UAVs) via in-flight energy harvesting from overhead electrical distribution power lines, and develops the flight dynamics and control framework to support centimeter-scale longitudinal powerline frequency tracking. The dynamics framework models the UAV's shape adaptive structure, aerodynamic forces, and control inputs, and applies the coupled flight mechanics framework to low clearance tracking of powerline contours. This study develops a "trajectory to shape-adaptive UAV" controller design approach for longitudinal powerline tracking through local spatial frequency matching. The frequency-matching approach dynamically regulates the aircraft modes' frequency to the powerline catenary spatial frequency using a generalized parameter linearization approach. Performance is assessed on an example UAV implementing camber and thickness morphing by quantifying clearance distance from neighborhood to high voltage powerline environments and across span and chord combinations. This approach achieves alternating periods of low-clearance tracking and antiphase oscillation, with 34% of the powerline having tracking error less than 1m. Airfoil thickness increase has a stronger effect over Phugoid mode wavelength than thickness decrease. Wingspan, chord, and powerline parameter sensitivities are quantified, providing a foundation for near-field long-distance powerline tracking and energy harvesting.

Figures (19)

• Figure 1: Powerline unmanned surfing concept for long range fixed wing UAV range extension and navigation.
• Figure 2: This paper's coverage: flight dynamics model development, powerline geometry environment, and controller development.
• Figure 3: Powerline geometry used in this study tranline_designmanual.
• Figure 4: Controller architecture for phugoid-catenary mapping
• Figure 5: Shape adaptive solver in loop method of aerodynamic parameter calculation