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Informal Seminar by Jong-Yeob Shin |
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Date: November 2, 2005
Time: 12:00pm
Location: NIA, Rm 137
Spin Stabilized Flying Test Platform Development
Jong-Yeob Shin, NIA
An approach for controlling the attitude of statically unstable thrust-levitated
vehicles in hover or slow translation will be presented. The large thrust vector that characterizes such vehicles can be modulated to provide control forces and moments to the airframe, but such modulation is accompanied by significant unsteady flow effects under large disturbance environment.
These effects are too difficult to be modeled in a mathematical way. Even if the thrust vectoring machinery has sufficient bandwidth for stabilization,
practical use of thrust vectoring in closed-loop attitude stability is limited due to disturbance of the environment.
The spin stabilization approach described here is based on using internal angular momentum transfer devices for stability, augmented by thrust vectoring for trim and other "outer loop" control functions. The three main components of this approach are:
- a z-body axis angular momentum bias enhances dynamic stability in attitude, reducing the amount of thrust-vector control activity needed for stabilization,
- optionally, gimbaled control moment gyros provide high-bandwidth control torques for additional stabilization, or agility,
and
- the resulting strongly coupled system dynamics are controlled by a multivariable controller. A spin stabilized flying test platform flight is described, and nonlinear simulation results are provided that demonstrate the efficacy of the approach.
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