UC San Diego

Small Unmanned Air Vehicles (UAVs) are versatile tools with both civilian and military applications. Fixed wing UAVs require forward airspeed to remain airborne, usually resulting in constant energy expenditure to loiter over targets. A UAV capable of perching could reduce energy expenditure by settling on a site near the target, thus increasing mission duration. Avian perching techniques were observed to build a hypothesis for the biological control techniques employed during the landing maneuver. Variation of wing sweep for pitch control was identified as a contributing control method, and selected for study. A biologically-inspired aircraft was designed with variable wing sweep, and modeled using a combination of MATLAB and Athena Vortex Lattice (AVL) to predict pitching response due to wing sweep. A small remote controlled prototype was built with variable wing sweep in addition to standard flight control surfaces. An onboard microcontroller and inertia measurement unit (IMU) were used to record pitch and wing sweep data during flight. Pitch response to wing sweep was observed, and a proportional integral derivative (PID) control system was designed to successfully use wing sweep for closed loop pitch control