Mathematical Modeling and Experimental Identification of an Unmanned Helicopter Robot with Flybar Dynamics

This paper presents a mathematical model for a model-scale unmanned helicopter robot, with emphasis on the dynamics of the flybar. The interaction between the flybar and the main rotor blade is explained in detail; it is shown how the flapping of the flybar increases the stability of the helicopter robot as well as assists in its actuation. The model helicopter has a fast time-domain response due to its small size, and is inherently unstable. Therefore, most commercially available model helicopters use the flybar to augment stability and make it easier for a pilot to fly. Working from first principles and basic aerodynamics, the equations of motion for full six degree-of-freedom with flybar-degree of freedom are derived. System identification experiments and results are presented to verify the mathematical model structure and to identify model parameters such as inertias and aerodynamic constants. © 2004 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34939/1/20002_ftp.pd

Development of a Forced Oscillation Test Technique for Determination of MAV Stability Characteristics

This thesis presents the development and validation of a forced oscillation test technique for the determination of Micro Air Vehicle (MAV) stability characteristics. The test setup utilizes a scotch yoke mechanism to oscillate a MAV along a single axis at a fixed amplitude and frequency. The aerodynamic reaction forces to this sinusoidal perturbation are measured and converted into meaningful stability parameters. The purpose of this research is to demonstrate that forced oscillation testing is an effective means of measuring the stability parameters of a MAV. Initial tests show that the forced oscillation test process is returning results which match the expected trends. Comparison of the results to an analytical model of blade flapping shows that the experimental results are of the proper magnitude. It can be concluded from this research that forced oscillation testing is a feasible method for determining the stability parameters of MAVs