In this thesis, A nonlinear methodology for the control of the highly
maneuverable, high performance aircraft HARV (F-18) is studied by using sliding-mode
control (SMC). This control law, which takes a continuous function when the
input constraints are not considered, satisfies the reachability condition by which
concerned states are driven to their sliding surfaces. Especially, this SMC is
generalized for the so-called (square) uncoupled multi-input multi-output (MIMO)
system by the use of error dynamics and applied directly to the nonlinear aircraft
system without linearizing the system.
For the practical application of the SMC to aircraft with input constraints, two
control schemes are used, considering that variations of pitch rate q directly affect
variations of the angle of attack. The first scheme consists of an ��-q control for the
fast response. The second scheme consists an a-control for making the output
approach its sliding surface slowly by setting boundary layers and adjusting reachable
speeds to the sliding surface.
Robustness to parameter uncertainties and disturbances is also studied for the
SMC. Especially, when the effect of parameter uncertainties is severe, then multiple
boundary layers are set in the neighborhood of sliding surface, in which different
reachable speeds to the sliding surface are used to sustain the concerned state within
the boundary layer and to reduce the effect of chattering. / Graduation date: 1994
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/35615 |
| Date | 13 July 1993 |
| Creators | Koo, Chang Sul |
| Contributors | Mohler, Ronald R. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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