Feasibility study of a circularly towed cable-body system for UAV applications

摘要

This paper presents a feasibility study for end-body positioning maneuvers using a towed cable-body system where a fixed wing Unmanned Aerial Vehicle (UAV) is stabilized in a steady-state circular motion. As high precision maneuvers such as object pickup/dropoff are typically performed by rotorcraft UAVs, a successful fixed-wing concept would greatly increase the possible range for this type of operation and enable missions into more remote locations. Circularly towed cable-body systems have been shown capable, both analytically and experimentally, of maintaining equilibrium configurations with the towed endbody stabilized in a small orbit respective to a point on the ground. However, no known efforts consider small to medium scale UAV operations for object pickup/dropoff. It is a primary goal of this paper to identify key parameters to consider when selecting a UAV and towcable system to use for high precision maneuvers, specifically to consider the achievable steady state configurations for circularly towed UAV systems. The equations of motion for the towed cable are developed based on a Lumped Parameter Model (LPM). An optimization problem was formulated in order to determine configuration parameters for the towed system that minimizes the steady-state orbit of the towed endbody while staying within the performance constraints that apply to the towing UAV. It is shown feasible to achieve sufficiently small orbits of the endbody to warrant considering the concept further for precision maneuvers.