Switched System Stability and Stabilization for Fighter Aircraft

This thesis presents stability and performance analyses for switched systems subject to arbitrary and constrained switching signals. Analysis techniques based on common quadratic Lyapunov functions are first introduced as these can be very effective in coping with arbitrary, unconstrained switching signals. However, for systems subject to switching signals which are time constrained, less conservative tools, based on dwell-time analysis, are introduced and extended for the computation of L2-gain estimates. Robust L2-gain and H2 state-feedback controllers syntheses follow from this analysis. An L2 performance analysis tool, for piecewise linear systems, is also given and used to the design of piecewise linear state-feedback controllers. The performance analysis and controller synthesis techniques mentioned above have been applied to the control of the longitudinal axis of the ADMIRE aircraft fighter benchmark model. Simulations show that a switched state-feedback controller provides better tracking than a simple LQR feedback gain.