Nonlinear Autopilot, 6 degrees of freedom, missile, interceptor
Nonlinear stabilization and control autopilots are capable of sustaining nominal performance throughout the entire fight envelope an interceptor missile may encounter during hostile engagements and require no gain scheduling to maintain autopilot stability. Due to non minimum phase conditions characteristic of tail controlled missile airframes, a separation of time scales within the dynamic equations of motion between rotational and translational differential equations was enforced to overcome unstable effects of non minimum phase. Dynamic inversion techniques are then applied to derive linearizing equations which, when injected forward into the plant result in a fully controllable linear system. Objectives of the two time scale control architecture are to stabilize vehicle rotational rates while at the same time controlling acceleration within the lateral plane of the vehicle under rapidly increasing dynamic pressure. Full 6 degree of freedom dynamic terms including all coriolis accelerations due to translational and rotational dynamic coupling have been taken into account in the inversion process. The result is a very stable, nonlinear autopilot with fixed control gains fully capable of stable nonlinear missile control. Several actuator systems were also designed to explore the destabilizing effects second order nonlinear actuator characteristics can have on nonlinear autopilot designs.
Master of Science in Electrical Engineering (M.S.E.E.)
College of Engineering and Computer Science
Electrical Engineering and Computer Science
Length of Campus-only Access
Masters Thesis (Open Access)
Snyder, Mark, "Nonlinear Stabilization And Control Of Medium Range Surface To Air Interceptor Missiles" (2009). Electronic Theses and Dissertations. 4180.