Abstract:
Multirotor UAS spanning Groups 3 and 4 have received increased attention as candidates for tactical resupply missions due to their VTOL capability and payload capacity. The objective of this work is to better understand how the parameters of multicopter UAS flight dynamics models scale with size in support of expanding the Army's unmanned aerial reconnaissance capability. A family of coaxial multirotor UAS spanning Groups 2 and 3 have been flight tested to gather data for flight dynamics modeling and validation. These UAS consist of the TRV-80, TRV-150, and the subscale Eagle platform. A series of test points including static stability, trim shot, frequency sweeps, doublets, and maximum climb rate maneuvers were collected. Wind data was simultaneously collected using a 3-axis ultrasonic anemometer to characterize wind conditions and characteristics during testing. Flight data were collected in varying payload configurations ranging from 0-120 pounds and at flight conditions ranging from hover to 50 knots. Point state space models were identified from frequency sweeps and verified using doublet time histories. Point models of the TRV-150 were combined with trim data and experimentally measured moments of inertia to develop a stitched simulation model. The stitched model was used to extrapolate for the flight tested off-nominal payload configurations for analysis. The unstable roll and pitch hover eigenvalues between the vehicles within the TRV family and smaller Group 1-2 UAS were analyzed and compared to Froude-scaled results to establish trends based on vehicle aspect ratio.