Characteristic Length and Dynamic Time Scale Associated with Aircraft Pitching Motion

Pitch Dynamics of Unmanned Aerial Vehicles

“…The foundational material was presented by Phillips and Niewoehner. 27 Variations of the procedure proposed for locating the stick-fixed maneuver point of an unmanned aircraft are commonly used for locating the stick-fixed maneuver point of manned aircraft. 35 -38 Furthermore, variations of the filar pendulum have been used to experimentally determine the mass moments of inertia of airplanes for nearly a century.…”

“…35 -38 Furthermore, variations of the filar pendulum have been used to experimentally determine the mass moments of inertia of airplanes for nearly a century. 41 -47 What this paper does provide is a consolidation of the analytical details associated with procedures that can be used to experimentally determine the traditional control anticipation parameter and the recently-proposed dynamic margin 27 for an unmanned aircraft. The procedures and required tools are simple enough to be implemented with an RC aircraft in an educational setting where resources for extensive flight testing are often limited.…”

“…Continuing to follow Phillips and Niewoehner, 27 we define the dimensionless dynamic rates and accelerations…”

“…Flight-test data reported in U.S. military specifications 3,4 show that flying qualities of manned airplanes do not scale with traditional nondimensional parameters. 27 The use of more physically significant dynamic length and time scales will likely prove advantageous as we begin to develop dynamic stability requirements for UAVs, which will span a range of vehicle size several orders of magnitude greater than the extent spanned by manned aircraft.…”