GN&C Design and Analysis Branch, NASA Johnson Space Center
16 February 1999 – 16 February 2000
Co-P.I. Donald T. Ward
Total award $64,307
One of the flight control methodologies which will permit this capability is Dynamic Inversion. Also called Feedback Linearization, it is a non-traditional methodology for synthesizing closed-loop control laws. As opposed to traditional techniques whereby the nonlinear plant is separated into several linearized models at discrete operating points and a closed-loop controller is synthesized for each one, Dynamic Inversion seeks to synthesize a global control law from a single nonlinear model. It has been applied to paper studies of controllers for aircraft such as the F-18 HARV, and has been flown successfully on the X-36.
Specific questions to be answered by this research are:
- Is the methodology suitable for a flight vehicle with an extreme range of operating conditions (hypersonic-supersonic-transonic-subsonic) like the X-38?
- Is the method suitable for rapid prototyping? Specifically, is software validation of the resulting control laws straightforward and rapid?
- For which type of applications and in what circumstances (range of operating conditions or flight regimes) is output feedback suitable as opposed to full-state feedback?
- Is it sufficiently robust to handle flight vehicle uncertainties (aerodynamics and mass properties), atmospheric distrurbances, and effector failures?
Working with me on this program is Graduate Research Assistant:
- Dai Ito