Accession Number : ADA620210


Title :   Onboard Flow Sensing For Downwash Detection and Avoidance On Small Quadrotor Helicopters


Descriptive Note : Conference paper


Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC


Personal Author(s) : Yeo, Derrick W ; Sydney, Nitin ; Paley, Derek A ; Sofge, Donald


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a620210.pdf


Report Date : Jan 2015


Pagination or Media Count : 12


Abstract : Small rotary-wing UAVs are susceptible to gusts and other environmental disturbances that a ect inow at their rotors. Inow variations cause unexpected aerodynamic forces through changes in thrust conditions and unmodeled blade apping dynamics. This pa- per introduces an onboard, pressure-based ow measurement system developed for a small quadrotor helicopter. The probe-based instrumentation package provides spatially dis- tributed airspeed measurements along each of the aircraft- xed axes. Lateral and vertical windspeed estimates enable the development of disturbance-tolerant ight control strate- gies. The focus of this paper is vertical ow disturbances such as those caused by the downwash of a second vehicle. Real-time velocity measurements are incorporated into a recursive Bayesian estimator to localize a nearby rotorcraft using its downwash. A path planner developed for proximity ight is demonstrated through indoor ight testing with multiple vehicles to safely guide an instrumented quadrotor around the downwash of nearby rotorcraft.


Descriptors :   *AERODYNAMICS , *FLOW , *HELICOPTERS , *ROTARY WING AIRCRAFT , AVOIDANCE , BLADES , CONTROL , DETECTION , DOWNWASH , ENVIRONMENTS , INSTRUMENTATION , MEASUREMENT , ONBOARD , REAL TIME , ROTORS , SYMPOSIA , THRUST , VEHICLES , VELOCITY , VERTICAL ORIENTATION


Subject Categories : Aerodynamics
      Helicopters


Distribution Statement : APPROVED FOR PUBLIC RELEASE